# MBtek UNI 60 Documentation

> Complete MBtek UNI 60 (200K BTU) wood gasification boiler documentation: specifications, clearances, installation, TIS Tronic 260U controller setup, operation, maintenance and troubleshooting.

Product: UNI 60 Wood Boiler, 200K BTU (UNI-60) — Wood gasification boiler
Manufacturer: MBtek — https://mbtek.com
Buy: https://mbtek.com/collections/wood-boilers/products/uni-60-boiler-200k-btu
Support: 888-301-0737 · info@mbtek.com
Documentation: https://uni.sonicar.tech/
Last reviewed: 2026-09-23

# UNI 60 wood boiler documentation (/docs)



**The MBtek UNI 60 is a 200,000 BTU wood gasification boiler that heats up to 5,000 ft² of hydronic space heating and domestic hot water from split firewood, coal or woodchips.** This site is the complete manual: it takes the boiler from the delivery crate through planning, installation, controller setup, first firing, and everything that follows in service.

<SpecGrid
  items="[
  { label: 'Heat output', value: '85–205 KBTU' },
  { label: 'Heated area', value: 'Up to 5,000 ft²' },
  { label: 'Water volume', value: '40 gal' },
  { label: 'Firebox', value: '58 gal' },
  { label: 'Max log length', value: '26 in' },
  { label: 'Weight', value: '1,224 lb' },
  { label: 'Connections', value: '2 in' },
  { label: 'Flue outlet', value: '8 in' },
  { label: 'Controller', value: 'TIS Tronic 260U' },
]"
/>

<Figure src="/img/boiler/hero.webp" alt="MBtek UNI 60 wood gasification boiler shown with a stack of split firewood" caption="The UNI 60 — four-door steel body with the TIS Tronic 260U controller mounted on the top panel." width="800" height="800" max="480" />

## How to read this documentation [#how-to-read-this-documentation]

**Read it in order the first time.** The sidebar follows the real sequence of a UNI 60 project, and every section ends by pointing at the next one.

<Cards>
  <Card title="1 · Get started" href="/docs/start/quick-start" description="Quick start checklist, how gasification works, full specifications, delivery contents and the safety rules." />

  <Card title="2 · Plan the installation" href="/docs/planning/boiler-room" description="Boiler room clearances, chimney sizing, hydronic scheme, buffer tank, hot water and fuel storage." />

  <Card title="3 · Install" href="/docs/installation/positioning" description="Position, pipe, fill, wire the sensors and pumps, mount the controller and commission the boiler." />

  <Card title="4 · Set up the controller" href="/docs/controller/overview" description="TIS Tronic 260U first start, MBtek recommended settings, operating modes, hot water and alarms." />

  <Card title="5 · Operate" href="/docs/operation/first-firing" description="First firing, loading the firebox, choosing and drying fuel, and end-of-season shutdown." />

  <Card title="6 · Maintain and troubleshoot" href="/docs/maintenance/schedule" description="Cleaning schedule, chimney care, spare parts, alarm codes and a symptom-first fault guide." />
</Cards>

## Who this is for [#who-this-is-for]

**This documentation is written for the installer first and the owner second.** Some steps are legally and practically restricted:

| Task                                 | Who may do it                                  |
| ------------------------------------ | ---------------------------------------------- |
| Heating system design                | Qualified hydronic heating professional        |
| Boiler and pipework installation     | Qualified heating installer                    |
| Electrical connection                | Licensed electrician                           |
| First firing and commissioning       | Trained installer or service technician        |
| Daily loading, ash removal, cleaning | The owner, once trained on the unit            |
| Warranty repair                      | MBtek-accredited service centre or distributor |

<Callout type="warn" title="Commissioning affects your warranty">
  The warranty card must be filled in with the commissioning date by the qualified installer. A boiler
  commissioned outside these instructions, or run on an open heating system, can lose warranty cover.
  See [Warranty](https://uni.sonicar.tech/docs/support/warranty).
</Callout>

## What the UNI 60 is not [#what-the-uni-60-is-not]

**It is an indoor, closed-system, solid-fuel boiler — not an outdoor furnace and not a standalone appliance.** Planning around those limits early avoids expensive rework:

* It must be installed **indoors**, with natural or forced draft.
* It must run on a **closed** heating system with an expansion tank and a safety relief valve. Open systems corrode the body quickly and void the warranty.
* It needs **230 V mains power** for the controller and fan. It is not an off-grid boiler; if you need one, look at the non-gasification PRO series on [mbtek.com](https://mbtek.com/collections/wood-boilers).
* It needs **thermal storage or a carefully designed load** — a full firebox releases more heat than most buildings need at that moment.

## Naming note [#naming-note]

**In the original factory boiler manual the UNI 60 appears as "UNI 55".** The model was renamed for the North American market; the technical data is identical — 85–205 KBTU, 40 gal water volume, 58 gal firebox, 2 in connections, 8 in flue. Where this documentation and the scanned manual disagree, the figures published on the current [MBtek specification sheet](https://uni.sonicar.tech/docs/start/specifications) are authoritative.

<NextStep href="/docs/start/quick-start" title="Quick start">
  The one-page checklist of every stage, in order.
</NextStep>


# Alarms (/docs/controller/alarms)



**Alarms appear directly on the main screen and are indicated by a pulsing red LED on the right of the front panel.** Press `F` to open the list of alarms that have occurred, `UP` / `DOWN` to scroll, and `STOP` to delete errors.

<Figure src="/img/controller/alarm-list.jpg" alt="Controller main screen showing an alarm condition" caption="<><b>Figure 5.</b> An alarm on the main screen — the footer shows LIST and ALARM.</>" source="TIS Tronic 260U manual §6" width="291" height="228" max="300" />

<Figure src="/img/controller/alarm-detail.jpg" alt="Controller screen showing the list of alarms that have occurred" caption="<><b>Figure 6.</b> The alarm list screen — scroll with the arrow buttons, CLEAR deletes the error.</>" source="TIS Tronic 260U manual §6" width="291" height="228" max="300" />

## Alarm reference [#alarm-reference]

| Alarm                                                    | What it means                                                                                                    | What to check                                                                                                     |
| -------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- |
| **Boiler temperature measurement error**                 | The `T1` sensor is missing or damaged                                                                            | Sensor seated in the immersion well, wiring at `T1`, sensor continuity (KTY-81-210)                               |
| **HUW overheating**                                      | The temperature in the hot water tank has exceeded **85 °C**                                                     | HUW pump operation, tank sensor position on `T2`, HUW setpoint and temperature-increase value                     |
| **Temperature measurement error, HUW**                   | The `T2` sensor is missing or damaged                                                                            | Wiring at `T2`, sensor continuity                                                                                 |
| **Exhaust gas temperature measurement error**            | The `T3` sensor is missing or damaged                                                                            | PT1000 fitted and wired to `T3`; the sensor is activated in the menu but not physically present is a common cause |
| **Lack of fuel**                                         | The quenching condition has been met — the fire is out                                                           | Reload, then check fuel quality and the fuel shortage thresholds                                                  |
| **Failed fireup**                                        | The time set in *firing-up time* expired without the boiler temperature rising above shutdown temperature + 2 °C | Draft, fuel moisture, fan operation, minimum fan speed, firing-up time setting                                    |
| **Exceeding the boiler emergency temperature threshold** | Boiler temperature has exceeded **94 °C**. The device switches to boiler protection mode                         | Pump operation, flow path, zone actuators, bypass, boiler cooling temperature setting                             |
| **Overheating STB**                                      | The external safety thermostat has tripped. To clear, boiler temperature must fall below **60 °C**               | See below                                                                                                         |

## STB overheating in detail [#stb-overheating-in-detail]

**The STB is an independent bimetallic sensor that cuts the fan when the water rises above roughly 90 °C.** It is hardware — it acts whatever the software is doing.

Per **PN-EN 303-5:2012**, when the water temperature drops back to a safe value it is *not* possible for the fan to turn on by itself. Both of these must happen:

<Steps>
  <Step>
    The water temperature in the boiler drops below **60 °C**.
  </Step>

  <Step>
    The error is **manually reset** on the control panel with `STOP`.
  </Step>
</Steps>

### Common causes [#common-causes]

| Cause                                       | Fix                                                                        |
| ------------------------------------------- | -------------------------------------------------------------------------- |
| Pump failed or not running                  | Check `Q3` output, pump power, and the 220 VAC relay for 120 V circulators |
| Every zone closed at once, no bypass        | Fit a flow bypass                                                          |
| Pump start temperature set too high         | MBtek value is 35 °C / 95 °F                                               |
| Boiler cooling temperature set too high     | MBtek value is 78 °C / 172 °F                                              |
| Air lock in the boiler or distribution loop | Vent the system                                                            |
| Power outage during a burn                  | Expected behaviour — reload after it clears                                |

If you need the boiler to operate at a higher temperature, a **DZT-2** thermal protection sensor opens at 200 °F / 95 °C instead of the DZT-1's 185 °F / 85 °C. Order from MBtek (Parts — UNI 15-40-60-95) and connect to `I1`.

## Sensor fault diagnosis [#sensor-fault-diagnosis]

**A sensor alarm means missing or damaged — either the sensor itself or the wire.**

<Steps>
  <Step>
    Disconnect the controller from the mains.
  </Step>

  <Step>
    Remove the top cover and check the connector at the relevant terminal. A correctly installed wire cannot be pulled out without pressing the terminal clip.
  </Step>

  <Step>
    Check the sensor against its resistance/temperature curve. The boiler and HUW sensors are KTY-81-210; the exhaust sensor is a PT1000.
  </Step>

  <Step>
    Replace the sensor if it is out of tolerance. Sensors have no polarity.
  </Step>
</Steps>

Replacement procedure and the terminal map are on [Electrical and sensors](https://uni.sonicar.tech/docs/installation/electrical).

## Boiler sensor resistance reference [#boiler-sensor-resistance-reference]

**Use this to check a suspect CT4 boiler sensor with a multimeter.**

| °C  | °F  | Typical Ω | °C  | °F  | Typical Ω |
| --- | --- | --------- | --- | --- | --------- |
| −20 | −4  | 1367      | 60  | 140 | 2597      |
| 0   | 32  | 1630      | 70  | 158 | 2785      |
| 20  | 68  | 1922      | 80  | 176 | 2980      |
| 25  | 77  | 2000      | 90  | 194 | 3182      |
| 30  | 86  | 2080      | 100 | 212 | 3392      |
| 40  | 104 | 2080      | 110 | 230 | 3607      |
| 50  | 122 | 2417      | 125 | 257 | 3915      |

<NextStep href="/docs/controller/wiring-reference" title="Wiring reference">
  The complete terminal map, sensor schedule and fuse specification.
</NextStep>


# Boiler settings (/docs/controller/boiler-settings)



**The boiler settings menu holds the parameters that define the boiler's safe envelope and its fire-up behaviour.** These are set once at commissioning and rarely touched afterwards.

## Temperature parameters [#temperature-parameters]

<Accordions>
  <Accordion title="Boiler hysteresis">
    **How many degrees below setpoint the controller switches back from supervision to operation** — that is, when the fan restarts.

    Example: with the boiler set to 60 °C and hysteresis 2 °C, the boiler switches from supervision to operating after the temperature drops to 58 °C.

    |                 |                 |
    | --------------- | --------------- |
    | Range           | 1 … 3 °C        |
    | Factory default | 2 °C            |
    | **MBtek value** | **2 °C / 5 °F** |
  </Accordion>

  <Accordion title="Maximum boiler temperature">
    **The maximum permitted boiler water temperature.** Shown above the ruler on the boiler temperature main screen.

    Above this value the regulator treats the boiler as unstable: external devices such as a room thermostat are **ignored** until operation stabilises, and **fan control functions are disabled**.

    |                 |                    |
    | --------------- | ------------------ |
    | Range           | 70 … 90 °C         |
    | Factory default | 85 °C              |
    | **MBtek value** | **80 °C / 176 °F** |
  </Accordion>

  <Accordion title="Boiler shutdown temperature">
    **When the boiler temperature drops below this value, the regulator switches off the fan and goes to STOP mode**, shown by the yellow LED.

    Shutdown can be caused by a shortage of fuel, a boiler malfunction, incorrect settings or a prolonged power outage.

    |                 |                   |
    | --------------- | ----------------- |
    | Range           | 30 … 45 °C        |
    | Factory default | 35 °C             |
    | **MBtek value** | **35 °C / 95 °F** |
  </Accordion>

  <Accordion title="Pump start temperature">
    **The boiler temperature above which all active pumps switch on.** Pumps switch off when the temperature drops 5 °C below this value.

    |                 |                   |
    | --------------- | ----------------- |
    | Range           | 35 … 60 °C        |
    | Factory default | 35 °C             |
    | **MBtek value** | **35 °C / 95 °F** |
  </Accordion>

  <Accordion title="Boiler cooling temperature">
    **The maximum temperature above which all circulation pumps in the heating system are started**, to shed heat.

    |                 |                    |
    | --------------- | ------------------ |
    | Range           | 70 … 85 °C         |
    | Factory default | 78 °C              |
    | **MBtek value** | **78 °C / 172 °F** |
  </Accordion>
</Accordions>

<Callout title="How the four temperatures stack">
  35 °C pumps start → 65 °C setpoint → 78 °C all pumps forced on → 80 °C external controls ignored,
  fan control disabled → \~90 °C STB cuts the fan (hardware) → 94 °C emergency alarm and boiler
  protection mode.
</Callout>

## Fan and combustion [#fan-and-combustion]

<Accordions>
  <Accordion title="Fan type">
    **Selects the fan model so the speed curve matches the hardware.** Choosing correctly avoids a "dead band" in which changing parameters produces no noticeable change in fan operation.

    |                         |                           |
    | ----------------------- | ------------------------- |
    | Available types         | 07 / DM85 · 06/145 / DM80 |
    | **MBtek value for UNI** | **WPA 07 / DM85**         |
  </Accordion>

  <Accordion title="Fan deceleration (slowdown) threshold">
    **How many degrees before the set temperature the fan starts slowing down.** Applies in all three operating modes.

    |                 |                   |
    | --------------- | ----------------- |
    | Range           | 3 … 30 °C         |
    | Factory default | 12 °C             |
    | **MBtek value** | **12 °C / 21 °F** |
  </Accordion>

  <Accordion title="Firing-up time">
    **The maximum time the fire-up stage may last.** The regulator considers ignition successful if the boiler temperature rises, within this time, above the boiler shutdown temperature + 2 °C.

    |                 |                  |
    | --------------- | ---------------- |
    | Range           | 30 … 120 minutes |
    | Factory default | 120 min          |
    | **MBtek value** | **120 min**      |

    If the time expires without success, the controller raises a **Failed fireup** alarm.
  </Accordion>

  <Accordion title="Brager Expert exhaust gases — firing-up time">
    **How long the exhaust gas temperature target is held at 300 °C**, driving the fan at maximum capacity for faster ignition. Only available when the operating mode is *Brager Expert exhaust gases*.

    |                 |                 |
    | --------------- | --------------- |
    | Range           | 0 … 250 minutes |
    | Factory default | 10 min          |
    | **MBtek value** | **10 min**      |
  </Accordion>

  <Accordion title="Boiler operating mode">
    Standard, Brager Expert or Brager Expert exhaust gases. See [Operating modes](./operating-modes.mdx).
  </Accordion>
</Accordions>

## Exhaust and fuel shortage [#exhaust-and-fuel-shortage]

<Accordions>
  <Accordion title="Exhaust gases temperature sensor">
    **Activates the exhaust gas temperature sensor.** An additional main screen appears and the regulator can operate in *Brager Expert exhaust gases* mode.
  </Accordion>

  <Accordion title="Fuel shortage detection method">
    **Selects how the boiler decides to switch into quenching mode** — from the boiler temperature sensor, or from the exhaust gas sensor. See [Quenching](./quenching.mdx).
  </Accordion>

  <Accordion title="Exhaust gases temperature for detecting fuel shortage">
    **The exhaust temperature below which the boiler will switch to extinguishing mode.** Only relevant when the exhaust-based detection method is selected.

    |       |            |
    | ----- | ---------- |
    | Range | 30 … 90 °C |
  </Accordion>

  <Accordion title="Fuel shortage detection time">
    **The countdown after which the boiler switches to extinguishing** if the exhaust gas temperature stays below the threshold above.

    |       |                 |
    | ----- | --------------- |
    | Range | 2 … 200 minutes |
  </Accordion>

  <Accordion title="Switching off the pump in case of fuel shortage">
    **Whether the central heating pump is switched off during extinguishing mode.**

    |         |          |
    | ------- | -------- |
    | Options | YES / NO |
  </Accordion>

  <Accordion title="Central pump off delay">
    **How long after entering extinguishing mode the central pump is switched off.** Only active when *Fuel shortage CH pump OFF* is set to YES.

    |       |                 |
    | ----- | --------------- |
    | Range | 5 … 120 minutes |
  </Accordion>
</Accordions>

<NextStep href="/docs/controller/hot-water" title="Hot water (HUW)">
  Summer and Winter modes, priority, hysteresis and the temperature-increase function.
</NextStep>


# Control panel (/docs/controller/control-panel)



**Six buttons and four indicators run the whole controller: hold `F` for three seconds to enter the menu, press `F` briefly to cycle between main screens.** Everything else follows from those two gestures.

<Figure src="/img/controller/panel.jpg" alt="Annotated TIS Tronic 260U control panel identifying the alarm, CH pump, HUW pump and fan indicators, the stop mode indicator, the F screen-switching and menu button, the STOP button, UP and DOWN buttons, the device operating indicator and the START button" caption="<><b>Panel view and character designation.</b></>" source="TIS Tronic 260U manual §3.1" width="739" height="341" />

## Indicators [#indicators]

| Indicator           | Meaning                                                                                              |
| ------------------- | ---------------------------------------------------------------------------------------------------- |
| **Warning / alarm** | A malfunction — overheating, or a damaged temperature sensor (short circuit or breakage). Pulses red |
| **CH pump**         | The central heating pump is running                                                                  |
| **HUW pump**        | The hot water pump is running                                                                        |
| **Fan**             | The fan is in operation. Glows until the set temperature is reached, and during purge operation      |
| **START**           | **Flashing** — ignition in progress. **Constant** — automatic operation mode                         |
| **STOP**            | The device is stopped. Yellow, constantly illuminated when inactive                                  |

## Buttons [#buttons]

<Accordions>
  <Accordion title="F — switch screens and enter the menu">
    **Press briefly** in normal operation to cycle through the main screens and observe the heating and hot water modules.

    **Hold for 3 seconds** to enter the controller menu.

    When editing a parameter, pressing `F` exits configuration mode.
  </Accordion>

  <Accordion title="START / WORK">
    Switches the controller to the operating state.

    In **manual mode**, turns a connected mechanism on and off.

    In the **menu**, on a YES screen, enters and edits the selected parameter, and confirms changes afterwards.
  </Accordion>

  <Accordion title="STOP">
    Stops the controller from the main temperature screens, and turns off connected devices in manual mode.

    In the **menu**, on a NO screen, cancels the selected parameter without saving. Pressing it again returns one level up.

    Also used to **reset alarm warnings**.
  </Accordion>

  <Accordion title="UP and DOWN">
    Navigate the menu, and increase or decrease the value of the selected parameter by one unit per press.

    **Press and hold** to change the value faster.
  </Accordion>
</Accordions>

## Reading a screen [#reading-a-screen]

<Figure src="/img/controller/display.jpg" alt="Annotated controller display identifying the main screen name, current parameter value, maximum parameter value, value range bar, minimum parameter value and set parameter value" caption="<><b>Display view and description.</b> Every main screen uses the same six elements.</>" source="TIS Tronic 260U manual §3.2" width="546" height="275" max="520" />

| Element                 | What it shows                                                 |
| ----------------------- | ------------------------------------------------------------- |
| Main screen name        | Which reading you are looking at — boiler, exhaust gas or HUW |
| Current parameter value | The large figure: the live measurement                        |
| Set parameter value     | The smaller orange figure: the target                         |
| Maximum parameter value | Top of the bar — the upper end of the adjustable range        |
| Minimum parameter value | Bottom of the bar — the lower end of the adjustable range     |
| Value range             | The bar itself, filled to the current reading                 |

## Main screens [#main-screens]

**Press `F` briefly to rotate through the main screens.**

<Figure src="/img/controller/main-screens.jpg" alt="Three controller main screens arranged in a cycle — hot water temperature, exhaust gas temperature and boiler temperature — with the F button at the centre" caption="<><b>Figure 1 — the main screens.</b> Press F to move between boiler temperature, exhaust gas temperature and hot water temperature.</>" source="TIS Tronic 260U manual §4.1" width="671" height="385" />

### Boiler temperature screen [#boiler-temperature-screen]

<Figure src="/img/controller/screen-boiler.jpg" alt="Boiler temperature main screen showing the current reading in large type, the set value beneath it in orange, and a vertical bar with the maximum and minimum limits" caption="<><b>Figure 2.</b> Large figure = current boiler temperature. Orange figure below = setpoint, changed with UP and DOWN. The values above and below the ruler are the range within which the setpoint can be changed.</>" source="TIS Tronic 260U manual §4.1" width="308" height="240" max="320" />

### Exhaust gas temperature screen [#exhaust-gas-temperature-screen]

<Figure src="/img/controller/screen-exhaust.jpg" alt="Exhaust gas temperature screen showing the current reading and a bar with a padlock symbol indicating the setpoint cannot be changed" caption="<><b>Figure 3.</b> A padlock on the bar means the set temperature cannot be changed — for example because STANDARD mode is active.</>" source="TIS Tronic 260U manual §4.1" width="308" height="241" max="320" />

### Inactive screens [#inactive-screens]

<Figure src="/img/controller/screen-inactive.jpg" alt="Greyed-out hot water main screen indicating the module is disabled" caption="<><b>Figure 4.</b> Greyed-out screens mean the module is not configured and is currently disabled. Enable it in the relevant menu — for the screen shown, the HUW menu.</>" source="TIS Tronic 260U manual §4.1" width="308" height="241" max="320" />

<Callout title="Changing the setpoint takes no menu">
  On the boiler temperature main screen, `UP` and `DOWN` change the boiler setpoint directly. The
  same is true of the hot water setpoint on the HUW main screen.
</Callout>

<NextStep href="/docs/controller/first-start" title="First start">
  Powering up for the first time and working through the initial setup.
</NextStep>


# First start (/docs/controller/first-start)



**Switch on at the back panel, wait for the welcome screen, then hold `F` for three seconds and work through six initial settings before the boiler is fired.** The controller starts in an inactive state — the yellow STOP light is on — which is exactly where you want it while you configure.

## Power up [#power-up]

<Steps>
  <Step>
    ### Switch on [#switch-on]

    Use the switch on the **back panel** of the controller.
  </Step>

  <Step>
    ### Wait for the welcome screen [#wait-for-the-welcome-screen]

    A welcome screen appears, followed by one of the main screens.
  </Step>

  <Step>
    ### Confirm it is inactive [#confirm-it-is-inactive]

    The controller is in inactive mode, indicated by the **yellow STOP light** on the front panel, constantly illuminated.
  </Step>

  <Step>
    ### Check the screens rotate [#check-the-screens-rotate]

    Press `F` briefly to move between the main screens. Greyed-out screens are modules that are not yet configured.
  </Step>
</Steps>

<Callout type="error" title="Do not press START yet">
  Configure the controller before the first fire. The factory defaults are generic across the whole
  TIS range and will not burn correctly in a UNI 60.
</Callout>

## Initial setup [#initial-setup]

**Hold `F` for 3 seconds to enter the main menu.** The most important settings are:

<Steps>
  <Step>
    ### Boiler operation mode [#boiler-operation-mode]

    <Figure src="/img/controller/menu-op-mode.jpg" alt="Controller menu row for boiler operation mode" source="TIS Tronic 260U manual §4.2" width="718" height="128" />

    Choose **Standard**, **Brager Expert** or **Brager Expert exhaust gases**. MBtek recommends *Brager Expert exhaust gases* for the UNI 60 — it requires the PT1000 sensor. See [Operating modes](./operating-modes.mdx).
  </Step>

  <Step>
    ### Fan type [#fan-type]

    <Figure src="/img/controller/menu-fan-type.jpg" alt="Controller menu row for fan type selection" source="TIS Tronic 260U manual §4.2" width="718" height="91" />

    Set to **WPA 07 / DM85** — the type used on UNI units. The other supported option is 06/145 / DM80.

    Selecting the correct type avoids a "dead band" in which changing the fan parameters produces no visible change in fan operation.
  </Step>

  <Step>
    ### Pump start temperature [#pump-start-temperature]

    <Figure src="/img/controller/menu-pump-start.jpg" alt="Controller menu row for pump start-up temperature" source="TIS Tronic 260U manual §4.2" width="718" height="93" />

    MBtek value: **35 °C / 95 °F**. All active pumps switch on above this boiler temperature and switch off when it drops 5 °C below.
  </Step>

  <Step>
    ### Exhaust gas sensor [#exhaust-gas-sensor]

    <Figure src="/img/controller/menu-exhaust-sensor.jpg" alt="Controller menu row for activating the exhaust gas temperature sensor" source="TIS Tronic 260U manual §4.2" width="719" height="91" />

    Activate it if the PT1000 is fitted. An additional main screen appears, and *Brager Expert exhaust gases* mode becomes available.
  </Step>

  <Step>
    ### Fuel shortage detection method [#fuel-shortage-detection-method]

    <Figure src="/img/controller/menu-fuel-shortage.jpg" alt="Controller menu row for fuel shortage detection method" source="TIS Tronic 260U manual §4.2" width="718" height="91" />

    Choose whether the boiler decides the fire is out from the **boiler temperature sensor** or the **exhaust gas sensor**. See [Quenching and fuel shortage](./quenching.mdx).
  </Step>

  <Step>
    ### Temperature scale [#temperature-scale]

    <Figure src="/img/controller/menu-temp-scale.jpg" alt="Controller menu row for temperature scale selection" source="TIS Tronic 260U manual §4.2" width="718" height="92" />

    Celsius or Fahrenheit. This documentation gives both; the controller's own ranges are stated in °C.
  </Step>
</Steps>

## Navigating the menu [#navigating-the-menu]

| Action                                | Buttons                |
| ------------------------------------- | ---------------------- |
| Enter the menu                        | Hold `F` for 3 seconds |
| Move through the list                 | `UP` / `DOWN`          |
| Step forward into a setting           | `START`                |
| Confirm a change                      | `START`                |
| Cancel without saving / go up a level | `STOP`                 |
| Return to the home screens            | Briefly press `F`      |

The menu is grouped into category sections: **User menu**, **Thermostat menu**, **HUW menu**, **Boiler settings**, **Brager Expert**, plus **Software version**, **Reset to factory settings** and **Language selection**.

<Callout title="Note the software version">
  Open the *Software version* item and write the number down. Support calls go faster when you know
  it.
</Callout>

## Reset to factory settings [#reset-to-factory-settings]

**There is a factory reset in the menu** — use it if a boiler has been mis-set and you want a clean baseline, then reapply the [MBtek recommended settings](./recommended-settings.mdx) immediately afterwards.

<NextStep href="/docs/controller/recommended-settings" title="Recommended settings">
  The exact values MBtek specifies for the UNI 60.
</NextStep>


# Hot water (HUW) (/docs/controller/hot-water)



**The hot water module is off until you switch it into Summer or Winter mode — the greyed-out HUW main screen is the sign it has never been configured.** Once active, it drives the pump on `Q4` from the tank sensor on `T2`.

<Figure src="/img/controller/huw-modes.jpg" alt="Controller menu showing the HUW pump operation mode options" caption="<><b>HUW menu → HUW operating Modes → Summer / Winter / OFF.</b></>" source="TIS Tronic 260U manual §4.4" width="720" height="146" />

Switching the hot water pump into Winter or Summer mode moves the home screen from inactive (grey background) into active mode. From that moment the HUW pump operates in the selected mode, and the set HUW temperature can be changed directly on the HUW main screen with `UP` and `DOWN`.

## Modes [#modes]

<Figure src="/img/install/note-huw-modes.jpg" alt="Note from the UNI install guide listing the four HUW modes: 1 disable the heating pump to fill the DHW faster, 2 simultaneous operation of heating and DHW pump, 3 enable DHW in summer without the central heating system, 4 disable DHW" caption="<><b>The four HUW modes as MBtek numbers them.</b> If the DHW sensor is disconnected, the mode cannot be changed.</>" source="UNI Install Guide, page 1" width="654" height="328" max="520" />

| # | Mode                    | Effect                                                  |
| - | ----------------------- | ------------------------------------------------------- |
| 1 | Winter with priority    | Disable the heating pump to fill the DHW faster         |
| 2 | Winter without priority | Simultaneous operation of heating and DHW pump          |
| 3 | Summer                  | Enable DHW in summer without the central heating system |
| 4 | Off                     | Disable DHW                                             |

<Callout type="warn" title="The sensor gates the mode">
  If the DHW sensor on `T2` is disconnected, the mode **cannot** be changed.
</Callout>

<Accordions>
  <Accordion title="Summer mode">
    **The main purpose of the boiler is to prepare hot water in the tank.**

    All other pumps are switched off — **except** when the boiler reaches a temperature higher than the *maximum boiler temperature* parameter, after which all pumps switch on to protect the boiler from overheating.
  </Accordion>

  <Accordion title="Winter mode">
    **Central heating pumps and the hot water pump operate simultaneously.**

    Switching to Winter activates the HUW priority, working hours and temperature increase settings below.
  </Accordion>

  <Accordion title="Turn off mode">
    **The HUW pump is turned off.** The grey screen is responsible for displaying information about the HUW temperature, but nothing is controlled.
  </Accordion>
</Accordions>

## Parameters [#parameters]

<Accordions>
  <Accordion title="HUW hysteresis">
    **How far the tank temperature must fall below its setpoint before the HUW pump restarts.**

    <Figure src="/img/controller/huw-hysteresis.jpg" alt="Controller menu path: HUW menu, HUW Hysteresis, range 1 to 15 degrees Celsius" caption="<><b>HUW menu → HUW Hysteresis → 1–15 °C.</b></>" source="TIS Tronic 260U manual §4.4" width="720" height="82" />

    Example: with the set temperature at 40 °C and hysteresis 2 °C, the pump starts working after the temperature drops to 38 °C.

    |                 |           |
    | --------------- | --------- |
    | Range           | 1 … 15 °C |
    | Factory default | 5 °C      |
  </Accordion>

  <Accordion title="HUW priority (Winter mode only)">
    **Setting this to "on" turns off the central heating pump, and the water in the hot water tank is heated first.** The hot water temperature gets a higher priority than the temperature set on the boiler.
  </Accordion>

  <Accordion title="HUW working hours (priority only)">
    **The maximum time the HUW pump will try to reach the set tank temperature.**

    When the tank temperature drops by 5 °C from the user-set value, the pump switches on again until the set temperature is reached. This parameter caps how long that attempt may run, so the central heating system does not cool down intensively while the tank is being heated.

    Available only when the HUW pump is running in Winter mode with priority enabled.

    |                 |                  |
    | --------------- | ---------------- |
    | Range           | 10 … 240 minutes |
    | Factory default | 30 min           |
  </Accordion>

  <Accordion title="Temperature increase for HUW">
    **How many degrees the boiler temperature may rise above its own setpoint to speed up hot water preparation.**

    Example: boiler set to 50 °C, HUW set to 60 °C, HUW temperature increase 5 °C → the boiler temperature will be raised to 65 °C during the hot water preparation period.

    |                 |           |
    | --------------- | --------- |
    | Range           | 5 … 15 °C |
    | Factory default | 5 °C      |
  </Accordion>
</Accordions>

## Alarms related to hot water [#alarms-related-to-hot-water]

| Alarm                              | Meaning                                        |
| ---------------------------------- | ---------------------------------------------- |
| HUW overheating                    | The temperature in the tank has exceeded 85 °C |
| Temperature measurement error, HUW | The `T2` sensor is missing or damaged          |

## Hardware [#hardware]

| Item              | Detail                                                               |
| ----------------- | -------------------------------------------------------------------- |
| Pump output       | `Q4`, rated 1 A                                                      |
| Tank sensor       | `T2`, 3 m lead, KTY-81-210                                           |
| Recommended tanks | APOLLO DHW80 (combined buffer + indirect), DHW250 in the full scheme |

For a 120 V circulator on `Q4`, wire it through the supplied 220 VAC relay block — see [Pump wiring](https://uni.sonicar.tech/docs/installation/pump-wiring).

<NextStep href="/docs/controller/thermostat" title="Room thermostat control">
  Cycling the central heating pump once the room is up to temperature.
</NextStep>


# Operating modes (/docs/controller/operating-modes)



**The mode decides what the fan is chasing: a water temperature, a water temperature via an adaptive algorithm, or an exhaust gas temperature.** Change it in **Boiler settings → Boiler operating mode**.

<Figure src="/img/controller/menu-op-mode.jpg" alt="Controller menu row for selecting the boiler operating mode" caption="Boiler settings → Boiler operating mode." source="TIS Tronic 260U manual §4.3" width="718" height="128" />

## Standard [#standard]

**The boiler operates in two stages: Operation and Supervision, entirely on the values you set.** No adaptation — what you configure is what it does.

**In Operation**, these settings determine the burn:

* Maximum fan capacity
* Minimum fan capacity
* Threshold fan deceleration

**In Supervision**, once the set temperature has been reached:

* Fan capacity in supervision
* Fan blowing time (purge time)
* Time between fan blowing cycles

The boiler moves back from Supervision to Operation when the water drops by the **boiler hysteresis** value. With a 60 °C setpoint and 2 °C hysteresis, the fan restarts at 58 °C.

<Callout title="The exhaust screen is locked in Standard">
  On the exhaust gas main screen, a padlock on the bar means the set temperature cannot be changed.
  Active STANDARD mode is one reason for that.
</Callout>

## Brager Expert [#brager-expert]

**A smart algorithm that automatically selects parameters to adapt the boiler's current output to the actual demand for thermal energy**, while constantly striving to reach the set boiler temperature.

Only two parameters are exposed in the user menu:

* Maximum fan capacity
* Minimum fan capacity

Everything else is chosen by the algorithm. Use this mode when no exhaust gas sensor is fitted.

## Brager Expert exhaust gases [#brager-expert-exhaust-gases]

**The algorithm automatically selects optimal fan settings to maintain a constant exhaust gas temperature.** This is what MBtek recommends for the UNI 60, with an exhaust setpoint of **160–240 °C / 320–464 °F**.

<Callout type="warn" title="Requires the PT1000 sensor">
  Operation in Brager Expert exhaust gases mode requires connecting the temperature sensor
  (**PT-1000**) to `T3` and activating it in the controller main menu. The sensor is **not** included
  in the regulator standard kit.
</Callout>

<Figure src="/img/controller/menu-exhaust-sensor.jpg" alt="Controller menu row for activating the exhaust gas temperature sensor" caption="Activate the exhaust gas sensor before the mode becomes available." source="TIS Tronic 260U manual §4.3" width="719" height="91" />

### Firing-up time [#firing-up-time]

**This mode adds one parameter: firing-up time.**

| Parameter                                    | Range     | Factory default | MBtek value |
| -------------------------------------------- | --------- | --------------- | ----------- |
| Brager Expert exhaust gases — firing-up time | 0–250 min | 10 min          | 10 min      |

It determines **how long the exhaust gas temperature target is held at 300 °C**. That drives the fan at the highest possible capacity, which ignites the fuel faster.

## Why target exhaust temperature? [#why-target-exhaust-temperature]

**Exhaust temperature is a better proxy for combustion quality than water temperature.**

* Water temperature tells you how much heat has *accumulated*; exhaust temperature tells you how the fire is burning **right now**.
* Too low an exhaust temperature means incomplete combustion and condensing flue gas — tar in the chimney.
* Too high means heat is going up the chimney instead of into the water.

Holding 160–240 °C keeps the boiler in the band where combustion is complete but the heat exchanger is still extracting usefully.

## Choosing [#choosing]

| Situation                                                                                           | Mode                            |
| --------------------------------------------------------------------------------------------------- | ------------------------------- |
| PT1000 fitted, normal UNI 60 installation                                                           | **Brager Expert exhaust gases** |
| No PT1000 fitted                                                                                    | **Brager Expert**               |
| You need full manual control for diagnosis, or the adaptive algorithm is fighting an unusual system | **Standard**                    |

## Mode-dependent parameters [#mode-dependent-parameters]

| Parameter                   | Standard | Brager Expert | Brager Expert exhaust |
| --------------------------- | -------- | ------------- | --------------------- |
| Maximum fan capacity        | ✓        | ✓             | ✓                     |
| Minimum fan capacity        | ✓        | ✓             | ✓                     |
| Fan capacity in supervision | ✓        | —             | —                     |
| Purge time                  | ✓        | —             | —                     |
| Pause between blowups       | ✓        | —             | —                     |
| Fan deceleration threshold  | ✓        | ✓             | ✓                     |
| Exhaust firing-up time      | —        | —             | ✓                     |
| Exhaust setpoint editable   | —        | —             | ✓                     |

<NextStep href="/docs/controller/user-menu" title="User menu">
  The five everyday fan parameters, with ranges and defaults.
</NextStep>


# TIS Tronic 260U overview (/docs/controller/overview)



**The TIS Tronic 260U is the electronic regulator that turns the UNI 60 from a wood stove into a controlled heat source.** It modulates the combustion fan, runs the pumps, prepares domestic hot water, and reacts to a room thermostat — all from a colour LCD with six buttons.

<Figure src="/img/controller/panel.jpg" alt="TIS Tronic 260U control panel showing the colour display with boiler temperature, four status indicators on the right, and six buttons below" caption="<><b>TIS Tronic 260U control panel.</b> Indicators, left to right on the right-hand column: alarm, CH pump, HUW pump, fan. Buttons: START, DOWN, UP, STOP, F.</>" source="TIS Tronic 260U manual §3.1" width="739" height="341" />

## What it controls [#what-it-controls]

| Function                           | Output / input |
| ---------------------------------- | -------------- |
| Combustion fan, variable speed     | `Q1`           |
| Central heating pump               | `Q3`           |
| Domestic hot water (HUW) pump      | `Q4`           |
| Boiler water temperature           | `T1`           |
| Hot water tank temperature         | `T2`           |
| Exhaust gas temperature (optional) | `T3`           |
| Safety thermostat STB              | `I1`           |
| Room thermostat                    | `I2`           |
| Additional alarm output (optional) | `X23`          |

## Three operating modes [#three-operating-modes]

**The mode determines what the fan is chasing.**

| Mode                            | The algorithm aims to…                                                                                           | Needs exhaust sensor? |
| ------------------------------- | ---------------------------------------------------------------------------------------------------------------- | --------------------- |
| **Standard**                    | Reach the set boiler temperature, running two stages — Operation and Supervision — on fixed user settings        | No                    |
| **Brager Expert**               | Reach the set boiler temperature, automatically selecting optimal settings to match output to actual heat demand | No                    |
| **Brager Expert exhaust gases** | Automatically select fan settings to maintain a **constant exhaust gas temperature**                             | **Yes** (PT1000)      |

MBtek's recommended settings for the UNI 60 assume **Brager Expert exhaust gases**. Full detail on [Operating modes](./operating-modes.mdx).

## Domestic hot water [#domestic-hot-water]

**The controller prepares hot water in Summer or Winter mode, with or without priority.** In Summer mode the boiler's only job is the tank; in Winter mode heating and hot water run together. See [Hot water](./hot-water.mdx).

## The safety chain [#the-safety-chain]

**The controller is not the last line of defence.** Three layers act in order:

<Steps>
  <Step>
    **Maximum boiler temperature** (user setting, MBtek recommends 80 °C / 176 °F). External devices such as the room thermostat are ignored until operation becomes stable, and fan control functions are disabled.
  </Step>

  <Step>
    **Boiler emergency threshold, 94 °C.** The controller raises an alarm and switches to boiler protection mode.
  </Step>

  <Step>
    **STB bimetallic sensor on `I1`, \~90 °C.** Hardware. It cuts the fan. Per PN-EN 303-5:2012 the fan cannot restart until the water is below **60 °C** *and* the alarm has been manually reset.
  </Step>
</Steps>

## Specification [#specification]

| Property                                | Value                                                                                  |
| --------------------------------------- | -------------------------------------------------------------------------------------- |
| Power                                   | 230 V / 50 Hz AC                                                                       |
| Power consumption (no external devices) | 4.5 W                                                                                  |
| Output loading — fan, CH pump, HUW pump | 1 A each                                                                               |
| Relative humidity                       | 30–75 %                                                                                |
| Ambient temperature                     | 5–40 °C / 41–104 °F                                                                    |
| Fuse                                    | 250 V, 3.15 A, 5 × 20 mm                                                               |
| Conformity                              | 2014/35/EU LVD, 2014/30/EU EMC · PN-EN 60730-1:2012, PN-EN 60730-2-9:2011 · CE 05/2020 |
| Manufacturer                            | BelKomin LLC, Grodno, Belarus                                                          |

<Callout type="warn" title="Where the regulator may be used">
  The regulator must not be used for boilers operating in installations that do not comply with
  **PN-EN 303-5**. It is designed to control a central heating boiler that has its own independent
  safety system — for example against overpressure in the system.
</Callout>

<NextStep href="/docs/controller/control-panel" title="Control panel">
  What every button, indicator and screen does.
</NextStep>


# Quenching and fuel shortage (/docs/controller/quenching)



**The controller detects a dead fire one of two ways — falling water temperature, or falling exhaust gas temperature — and the exhaust method is considerably more responsive.** Choose the method in **Boiler settings → Fuel shortage detection method**.

<Figure src="/img/controller/menu-fuel-shortage.jpg" alt="Controller menu path: Boiler Settings, Fuel shortage detecting method, with the options Boiler Sensor and Exhaust gases Sensor" caption="<><b>Boiler Settings → Fuel shortage detecting method → Boiler Sensor / Exhaust gases Sensor.</b> The choice only appears when a PT1000 exhaust sensor is connected.</>" source="TIS Tronic 260U manual §4.6" width="718" height="91" />

<Callout title="Default behaviour without an exhaust sensor">
  As standard, without a connected exhaust gas temperature sensor, boiler quenching (switching off)
  is based on the **boiler temperature**. The choice of method only appears once a PT1000 is
  connected.
</Callout>

## Method 1 — boiler temperature [#method-1--boiler-temperature]

**The boiler switches to quenching mode when the water temperature falls to the boiler shutdown temperature.**

| Parameter                   | Range    | Default | MBtek value       |
| --------------------------- | -------- | ------- | ----------------- |
| Boiler shutdown temperature | 30–45 °C | 35 °C   | **35 °C / 95 °F** |

When it triggers:

* the controller turns off the fan;
* the **START** diode on the front panel turns off;
* the **STOP** diode lights up.

<Figure src="/img/controller/quench-pump-off.jpg" alt="Controller menu path: Boiler Settings, Fuel shortage CH pump OFF, with the options YES and NO" caption="<><b>Boiler Settings → Fuel shortage CH pump OFF → YES / NO.</b> Whether the central heating pump stops when the fire goes out.</>" source="TIS Tronic 260U manual §4.6" width="718" height="92" />

<Figure src="/img/controller/quench-pump-delay.jpg" alt="Controller menu path: Boiler Settings, CH pump shutdown delay, range 5 to 120 minutes" caption="<><b>Boiler Settings → CH pump shutdown delay → 5–120 min.</b> Active only when CH pump OFF is set to YES.</>" source="TIS Tronic 260U manual §4.6" width="717" height="73" />

## Method 2 — exhaust gas temperature [#method-2--exhaust-gas-temperature]

**The boiler switches to quenching when the exhaust gas temperature falls below a set threshold and stays there for a set time.**

<Figure src="/img/controller/quench-exhaust-threshold.jpg" alt="Controller menu path: Boiler Settings, Exhaust gas temperature fuel shortage detection threshold, range 30 to 90 degrees Celsius" caption="<><b>Boiler Settings → Exhaust gas temperature fuel shortage detection threshold → 30–90 °C.</b></>" source="TIS Tronic 260U manual §4.6" width="717" height="73" />

<Figure src="/img/controller/quench-detection-time.jpg" alt="Controller menu path: Boiler Settings, Fuel shortage detection time parameter, range 2 to 200 minutes" caption="<><b>Boiler Settings → Fuel shortage detection time parameter → 2–200 min.</b></>" source="TIS Tronic 260U manual §4.6" width="717" height="73" />

| Parameter                                                  | Range     | What it does                                                                                                  |
| ---------------------------------------------------------- | --------- | ------------------------------------------------------------------------------------------------------------- |
| Exhaust gas temperature, fuel shortage detection threshold | 30–90 °C  | The exhaust temperature below which the boiler will switch to extinguishing mode                              |
| Fuel shortage detection time                               | 2–200 min | The delay — how long the exhaust temperature must fall or stay below the threshold before the controller acts |

When it triggers, the controller turns off the fan, the **START** diode turns off and the **STOP** diode lights up — the same as method 1.

<Callout title="Why the delay matters">
  Exhaust temperature dips briefly every time you open a door or the fire settles. The detection
  time stops those dips being mistaken for a dead fire.
</Callout>

## Pump behaviour during quenching [#pump-behaviour-during-quenching]

**Two settings decide what happens to the central heating pump when the fire goes out.**

| Parameter                 | Range     | Effect                                                                                          |
| ------------------------- | --------- | ----------------------------------------------------------------------------------------------- |
| Fuel shortage CH pump OFF | YES / NO  | Whether the CH pump is switched off during extinguishing mode                                   |
| CH pump shutdown delay    | 5–120 min | How long after entering extinguishing mode the pump stops. Requires the setting above to be YES |

**Leave the pump running if the boiler still holds useful heat.** The boiler's 40 gallons of water are worth circulating into the system rather than letting them sit.

## The related alarm [#the-related-alarm]

| Alarm             | Meaning                                                                                                                           |
| ----------------- | --------------------------------------------------------------------------------------------------------------------------------- |
| **Lack of fuel**  | The quenching condition above has been met                                                                                        |
| **Failed fireup** | The time specified in the firing-up time function expired without the boiler temperature rising above shutdown temperature + 2 °C |

See [Alarms](./alarms.mdx) for the full list and how to clear them.

<NextStep href="/docs/controller/alarms" title="Alarms">
  Every alarm the controller can raise, and what each one means.
</NextStep>


# MBtek recommended settings (/docs/controller/recommended-settings)



**Load these values before the first fire — the factory defaults are generic across the whole TIS range and will not burn well in a UNI 60.** These are MBtek's published settings from the UNI install guide.

<Callout type="warn" title="Set the fan type first">
  Set **Fan type = WPA 07 / DM85** before anything else. With the wrong fan type selected, the speed
  percentages below will not behave as described.
</Callout>

<Callout type="error" title="Below 140 °F you must fit a boiler protection valve">
  The use of a boiler protection valve is a **must** if using below 140 °F. The return water can
  generate heavy condensation on the unit, giving the impression of a water leak. See
  [Piping](https://uni.sonicar.tech/docs/installation/piping#why-return-protection-matters).
</Callout>

## User menu [#user-menu]

| Setting                              | MBtek value                 | Factory default |
| ------------------------------------ | --------------------------- | --------------- |
| Boiler setpoint                      | **65 °C / 149 °F**          | —               |
| Exhaust setpoint                     | **160–240 °C / 320–464 °F** | —               |
| Fan ON time (purge time)             | **10 s**                    | 10 s            |
| Fan OFF time (pause between blowups) | **5 min**                   | 5 min           |
| Maximum fan speed                    | **80 %**                    | 50 %            |
| Minimum fan speed                    | **40 %**                    | 10 %            |
| Fan performance in supervision       | **35 %**                    | 25 %            |

## Boiler settings [#boiler-settings]

| Setting                                      | MBtek value        | Factory default |
| -------------------------------------------- | ------------------ | --------------- |
| Brager Expert exhaust gases — firing-up time | **10 min**         | 10 min          |
| Fan slowdown (deceleration) threshold        | **12 °C / 21 °F**  | 12 °C           |
| Boiler hysteresis                            | **2 °C / 5 °F**    | 2 °C            |
| Maximum boiler temperature                   | **80 °C / 176 °F** | 85 °C           |
| Boiler shutdown temperature                  | **35 °C / 95 °F**  | 35 °C           |
| Pump start temperature                       | **35 °C / 95 °F**  | 35 °C           |
| Fan type                                     | **WPA 07 / DM85**  | —               |
| Firing-up time                               | **120 min**        | 120 min         |
| Boiler cooling temperature                   | **78 °C / 172 °F** | 78 °C           |

<Callout title="What MBtek changed from the defaults">
  Three settings differ from the factory values, and they matter:

  * **Maximum fan speed 50 % → 80 %** and &#x2A;*minimum 10 % → 40 %**: a UNI 60's fan needs more air than the generic default, and 10 % is low enough that the fan can hum without turning.
  * **Fan performance in supervision 25 % → 35 %**: keeps the coals alive through the pause between blowups.
  * **Maximum boiler temperature 85 °C → 80 °C**: a wider margin below the 94 °C emergency threshold and the STB's \~90 °C trip.
</Callout>

## Applying them [#applying-them]

<Steps>
  <Step>
    ### Enter the menu [#enter-the-menu]

    Hold `F` for 3 seconds.
  </Step>

  <Step>
    ### Set the fan type [#set-the-fan-type]

    **Boiler settings → Fan type → WPA 07 / DM85.**
  </Step>

  <Step>
    ### Set the operating mode [#set-the-operating-mode]

    **Boiler settings → Boiler operating mode → Brager Expert exhaust gases** (requires the PT1000 exhaust sensor activated). Without the sensor, use **Brager Expert**.
  </Step>

  <Step>
    ### Work down the boiler settings list [#work-down-the-boiler-settings-list]

    Apply every value in the boiler settings table above, in order.
  </Step>

  <Step>
    ### Work down the user menu list [#work-down-the-user-menu-list]

    Apply every value in the user menu table above.
  </Step>

  <Step>
    ### Set the boiler setpoint on the main screen [#set-the-boiler-setpoint-on-the-main-screen]

    Press `F` until the boiler temperature main screen is showing, then use `UP` / `DOWN` to set **65 °C / 149 °F**.
  </Step>

  <Step>
    ### Record what you set [#record-what-you-set]

    Note the software version and the final values on the commissioning paperwork.
  </Step>
</Steps>

<Callout type="warn" title="These are a starting point, not a guarantee">
  The boiler manual is explicit: to achieve high-quality and reliable operation the controller
  parameters must be optimised, and it is necessary to agree them with a professional instructed by
  your local distributor. Chimney draft, fuel and building load all shift the ideal values.
</Callout>

## Tuning notes [#tuning-notes]

| Symptom                                                    | Setting to look at                                                                                   |
| ---------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| Fan hums but does not turn                                 | Raise **minimum fan speed** to 40 %                                                                  |
| Fire dies during supervision                               | Raise **fan performance in supervision**, or shorten the **pause between blowups**                   |
| Boiler overshoots setpoint                                 | Lengthen the **pause between blowups**, shorten **purge time**, widen the **fan slowdown threshold** |
| Boiler cycles between operation and supervision constantly | Raise **boiler hysteresis** (range 1–3 °C)                                                           |
| Fire takes too long to establish                           | Raise the **Brager Expert exhaust firing-up time** from 10 min                                       |
| Controller reports failed fire-up                          | Raise **firing-up time** toward 120 min, or check fuel and draft                                     |

<SupportCta title="Want MBtek to check your settings?" />

<NextStep href="/docs/controller/operating-modes" title="Operating modes">
  What Standard, Brager Expert and Brager Expert exhaust gases each actually do.
</NextStep>


# Room thermostat control (/docs/controller/thermostat)



**The room thermostat controls the central heating circulation pump, not the fire.** When the room is cold the pump runs continuously; when the room is satisfied the controller cycles the pump instead of simply stopping it.

<Figure src="/img/controller/thermostat-setting.jpg" alt="Controller menu row for the room thermostat setting" caption="Thermostat menu." source="TIS Tronic 260U manual §4.5" width="720" height="104" />

## Wiring requirement [#wiring-requirement]

**The thermostat must be a dry contact on terminal `I2`**, and its logic must be:

* **Contacts closed** when the room temperature is **lower** than the user's setpoint → pump runs.
* **Contacts open** when the room temperature **is reached** → pump cycles.

For a 24 VAC thermostat, use a 24 VAC SPDT relay. Wiring detail is on [Room thermostat](https://uni.sonicar.tech/docs/installation/room-thermostat).

<Callout type="warn" title="Inverted logic is a common fault">
  For correct controller operation you need a thermostat that **disconnects** the contacts when the
  room temperature is reached and **connects** them when it is lower. Verify with a meter.
</Callout>

## Parameters [#parameters]

<Accordions>
  <Accordion title="CH room thermostat">
    Enables or disables the room thermostat function.
  </Accordion>

  <Accordion title="CH pump operating time">
    **How long the circulation pump runs during each cycle once the room temperature has been reached.**

    |                 |                  |
    | --------------- | ---------------- |
    | Range           | 30 … 250 seconds |
    | Factory default | 30 s             |
  </Accordion>

  <Accordion title="CH pump pause time">
    **The pause between the next circulation pump start-up.** Active only when the room temperature set on the thermostat has been reached.

    Setting this to **0** makes the circulation pump inactive — that is, it stops completely when the room is satisfied.

    |                 |                 |
    | --------------- | --------------- |
    | Range           | 0 … 240 minutes |
    | Factory default | 1 min           |
  </Accordion>
</Accordions>

## Why cycle instead of stop? [#why-cycle-instead-of-stop]

**Cycling keeps the emitters and the distribution loop from going cold and stratifying.** With a 30 s run every 1 min, water keeps moving gently, so:

* the room temperature stays even rather than sawtoothing;
* the boiler's return temperature does not crash, which protects it from condensation;
* and heat continues to leave the boiler, which is important on a solid-fuel appliance you cannot simply switch off.

Set the pause to 0 only when you have another path for boiler heat — a buffer tank or a hot water load.

## Overheat override [#overheat-override]

<Callout type="warn" title="The thermostat is ignored when the boiler is hot">
  If the boiler temperature exceeds the **maximum boiler temperature** value (MBtek recommends
  80 °C / 176 °F), room thermostat control is switched off to protect the boiler from overheating.
  The pump will run regardless of what the thermostat asks for.
</Callout>

This is deliberate. A wood fire cannot be turned off, so the controller must always be able to move heat out of the boiler.

<NextStep href="/docs/controller/quenching" title="Quenching and fuel shortage">
  How the controller decides the fire has gone out, and what it does then.
</NextStep>


# User menu (/docs/controller/user-menu)



**The user menu holds the five settings you are most likely to adjust after commissioning, and all five control the fan.** Hold `F` for 3 seconds, then open the user menu.

The number of parameters shown depends on the controller configuration — in Brager Expert modes some of these are taken over by the algorithm.

## Parameters [#parameters]

<Accordions>
  <Accordion title="Maximum fan output">
    **Defines the maximum fan speed in operation mode.**

    |                            |                               |
    | -------------------------- | ----------------------------- |
    | Range                      | Minimum setting + 1 % … 100 % |
    | Factory default            | 50 %                          |
    | **MBtek value for UNI 60** | **80 %**                      |
  </Accordion>

  <Accordion title="Minimum fan output">
    **Defines the minimum value of the fan speed.**

    |                            |                             |
    | -------------------------- | --------------------------- |
    | Range                      | 1 % … maximum setting − 1 % |
    | Factory default            | 10 %                        |
    | **MBtek value for UNI 60** | **40 %**                    |

    If the fan makes a humming sound and does not turn, this setting is too low. Raise it to 40 %.
  </Accordion>

  <Accordion title="Fan performance in supervision">
    **Sets the fan power during blowing-up when the boiler has reached the user set temperature and is running its cyclic start-ups.**

    |                            |             |
    | -------------------------- | ----------- |
    | Range                      | 1 % … 100 % |
    | Factory default            | 25 %        |
    | **MBtek value for UNI 60** | **35 %**    |
  </Accordion>

  <Accordion title="Purge time (fan ON time)">
    **How long, in seconds, the fan is turned on.** Activated when the set temperature is reached on the boiler.

    |                            |                |
    | -------------------------- | -------------- |
    | Range                      | 5 … 60 seconds |
    | Factory default            | 10 s           |
    | **MBtek value for UNI 60** | **10 s**       |

    **Attention:** the purge time should not be too long, or the boiler temperature will rise too high — but not too short, or the coals will go out.
  </Accordion>

  <Accordion title="Pause between blowups (fan OFF time)">
    **The length of the interval between the cyclic fan start-ups** that maintain combustion and blow down the boiler chamber once the set temperature has been reached.

    |                            |                |
    | -------------------------- | -------------- |
    | Range                      | 1 … 20 minutes |
    | Factory default            | 5 min          |
    | **MBtek value for UNI 60** | **5 min**      |

    **Attention:** the pause should not be too long, or the coals will be extinguished — but also not too short, or the boiler temperature will rise too high.
  </Accordion>
</Accordions>

## How supervision works [#how-supervision-works]

**Supervision is the boiler idling on a live fire.** Once the water reaches setpoint:

<Steps>
  <Step>
    The fan stops driving the fire.
  </Step>

  <Step>
    Every **pause between blowups** (5 min), the fan runs for the **purge time** (10 s) at the **supervision capacity** (35 %).
  </Step>

  <Step>
    That short pulse keeps the coals alive without adding meaningful heat.
  </Step>

  <Step>
    When the water drops by the **boiler hysteresis** (2 °C), the controller returns to full Operation.
  </Step>
</Steps>

Tuning those three numbers against each other is most of the art of running a wood boiler well.

## Other menus [#other-menus]

| Menu                      | Contents                                         | Page                                     |
| ------------------------- | ------------------------------------------------ | ---------------------------------------- |
| Thermostat menu           | Room thermostat control functions                | [Thermostat](./thermostat.mdx)           |
| HUW menu                  | Domestic hot water pump control                  | [Hot water](./hot-water.mdx)             |
| Boiler settings           | The full configuration list                      | [Boiler settings](./boiler-settings.mdx) |
| Brager Expert             | Advanced options for the Brager Expert algorithm | [Operating modes](./operating-modes.mdx) |
| Software version          | Current installed controller software            | —                                        |
| Reset to factory settings | Returns to defaults                              | —                                        |
| Language                  | Interface language                               | —                                        |

<NextStep href="/docs/controller/boiler-settings" title="Boiler settings">
  Hysteresis, temperature limits, fan type, fire-up time and quenching configuration.
</NextStep>


# Wiring reference (/docs/controller/wiring-reference)



**Everything you need at the board, in one place.** Disconnect the regulator plug from the 230 V supply before any repair work.

## Board diagram [#board-diagram]

<Figure src="/img/install/board-diagram.jpg" alt="TIS Tronic 260U board layout with power input, PE terminals, outputs Q1, Q3 and Q4, inputs I1 and I2, sensor terminals T1, T2 and T3, the X23 alarm header and the TR2_DISP panel connector" caption="<><b>Board view and connection diagram.</b> Power 230 V enters at L and N, bottom left.</>" source="TIS Tronic 260U manual §7.1" width="1324" height="1050" />

## Terminal map [#terminal-map]

<Figure src="/img/install/terminal-table.jpg" alt="Terminal designation table listing Q1 fan outlet, Q3 CH pump outlet, Q4 HUW pump output, I1 emergency thermostat STB, I2 central heating room thermostat, T1 boiler temperature sensor, T2 HUW temperature sensor, T3 exhaust gas temperature sensor, TR2_DISP panel connector, X23 additional alarm and minus plus AB alternative slot" caption="<><b>Terminal designations.</b></>" source="UNI Install Guide, page 1" width="1010" height="728" max="620" />

| Symbol       | Designation                             | Type               | Rating        |
| ------------ | --------------------------------------- | ------------------ | ------------- |
| `Q1`         | Fan outlet                              | Output, 230 V      | 1 A           |
| `Q3`         | Central heating pump outlet             | Output, 230 V      | 1 A           |
| `Q4`         | HUW pump output                         | Output, 230 V      | 1 A           |
| `I1`         | Emergency thermostat STB                | Input, dry contact | —             |
| `I2`         | Central heating room thermostat         | Input, dry contact | —             |
| `T1`         | Boiler temperature sensor               | Sensor             | KTY-81-210    |
| `T2`         | HUW temperature sensor                  | Sensor             | KTY-81-210    |
| `T3`         | Exhaust gas temperature sensor          | Sensor             | PT1000        |
| `TR2_DISP`   | Panel connector                         | Ribbon             | —             |
| `X23`        | Additional alarm (optional)             | Output header      | —             |
| `- + A B`    | Alternative slot for additional modules | Bus                | —             |
| `L` `N` `PE` | Power 230 V and earth                   | Supply             | 230 V / 50 Hz |

## Sensor schedule [#sensor-schedule]

| Sensor             | Terminal | Wire length | Type       |
| ------------------ | -------- | ----------- | ---------- |
| CH sensor (boiler) | `T1`     | 0.8 m       | KTY-81-210 |
| HUW                | `T2`     | 3 m         | KTY-81-210 |
| Exhaust gases      | `T3`     | —           | PT1000     |
| STB                | `I1`     | 1 m         | Bimetal    |

**Sensors have no polarity** — the wiring sequence is not significant.

<Callout type="warn" title="Exhaust sensor sold separately">
  The PT1000 exhaust gas sensor is not included in the regulator standard kit.
</Callout>

## Hydraulic and STB connection [#hydraulic-and-stb-connection]

<Figure src="/img/controller/hydraulic-stb.jpg" alt="Recommended hydraulic circuit showing the boiler with fan, STB and CH sensor, room thermostat, TIS Tronic 260u controller, central heating pump, thermostatic three-way valve, check valves, radiators, HUW pump and water tank" caption="<><b>STB connection options and the recommended hydraulic circuit.</b> The inset shows the CH sensor lowered into the immersion well with the STB above it. The diagram is approximate and simplified.</>" source="TIS Tronic 260U manual §7.3" width="745" height="427" />

## Fuse [#fuse]

<Figure src="/img/controller/fuse.jpg" alt="A 5 by 20 millimetre glass cartridge fuse" caption="<><b>Figure 7 — the fuse.</b> 250 V, 3.15 A, 5 × 20 mm. The holder is on the control unit motherboard, at the back of the regulator housing.</>" source="TIS Tronic 260U manual §7.4" width="708" height="279" max="380" />

| Property | Value  |
| -------- | ------ |
| Voltage  | 250 V  |
| Current  | 3.15 A |
| Diameter | 5 mm   |
| Height   | 20 mm  |

**Replace a blown fuse only with a new one of the same rating.** Fuse failure is not covered by warranty.

## Opening the housing [#opening-the-housing]

**Unscrew the fixing screws on the back of the housing, then remove the top cover.**

<Callout type="error" title="Isolate first">
  Before performing any repair work, be sure to disconnect the regulator plug from the 230 V power
  supply.
</Callout>

## Seasonal electrical check [#seasonal-electrical-check]

**Before the heating season and during it, check:**

* the technical condition of the wires;
* the fastening of the regulator;
* and clean it of dust and other contaminants.

## Disposal [#disposal]

The crossed-out wheeled bin symbol means the product must not be disposed of in regular waste bins. Return used equipment to a designated collection point for waste electrical and electronic equipment. The manufacturer's environmental registration number is 000002627.

<NextStep href="/docs/operation/first-firing" title="First firing">
  The controller is configured. Time to light it.
</NextStep>


# Chimney care (/docs/maintenance/chimney-care)



**Flue gas creates soot and condensation that lead to deterioration of joints — so chimney maintenance is a safety task, not just a draft task.** For safe and efficient operation of the boiler it is necessary to ensure the chimney is swept.

## What "good" looks like [#what-good-looks-like]

**The inside of the chimney should be smooth, without a condensation or soot deposit zone, for optimal draft without obstruction.**

Check for:

* soot and tar build-up narrowing the bore;
* condensation staining at joints and bends;
* corrosion at the joints — the first place acidic condensate attacks;
* any obstruction: nests, debris, collapsed liner.

## What changes the deposition rate [#what-changes-the-deposition-rate]

| Factor                 | Effect                                                         |
| ---------------------- | -------------------------------------------------------------- |
| **Fuel type**          | Wood deposits more than coal                                   |
| **Boiler temperature** | Lower temperatures condense more tar                           |
| **Operation mode**     | Long, air-starved burns deposit far more than hot, clean burns |
| **Fuel moisture**      | Wet fuel is the single biggest contributor                     |
| **Chimney insulation** | An exposed, uninsulated flue runs cold and condenses           |
| **Number of bends**    | Each bend costs draft and collects deposits                    |

<Callout title="The efficiency link">
  Soot and ash deposits on the walls reduce heat transfer and efficiency. A fouled chimney and a
  fouled heat exchanger usually arrive together, and both trace back to the same cause: burning wet
  wood, or running the boiler too cool.
</Callout>

## Choosing a chimney for maintainability [#choosing-a-chimney-for-maintainability]

**When choosing a chimney, consider:**

* compatibility with the boiler;
* the type of fuel;
* ease of assembly and disassembly for maintenance;
* and compliance with fire safety standards.

The number of chimney bends should be as small as possible.

Specification requirements are on [Chimney requirements](https://uni.sonicar.tech/docs/planning/chimney): 8 in minimum, stainless steel 316 acid-resistant, single wall in a brick channel, double-walled insulated if exposed, to EN 1856-1:2013 and EN 1856-2:2013.

## Checking draft [#checking-draft]

**Present a strip of paper to the ash pit — the strip should deviate to the side of the ash pit.**

Also confirm that the ventilation openings for inflow and exhaust have not been restricted or blocked.

If draft is poor:

| Cause                        | Fix                                                  |
| ---------------------------- | ---------------------------------------------------- |
| Cold chimney                 | Insulate exposed runs; use a chimney fan on start-up |
| Soot narrowing the bore      | Sweep                                                |
| Too many bends               | Re-route if possible                                 |
| Blocked ventilation openings | Clear them — the boiler needs combustion air         |
| Undersized flue              | Must be at least the boiler outlet diameter — 8 in   |

## Start-up smoke [#start-up-smoke]

**For best comfort and minimal fume migration in the house, use a chimney fan upon starting the boiler.** As a second option, smoke hoods.

<Callout type="warn" title="Keep the records">
  Maintain documentation of clearance distances and code compliance for insurance and reference
  purposes. Add your sweeping records to the same file.
</Callout>

<NextStep href="/docs/maintenance/parts-service" title="Parts and service">
  Fuse, sensors, consumables, and when to call MBtek.
</NextStep>


# Cleaning the boiler (/docs/maintenance/cleaning)



**Every millimetre of soot and ash between the fire and the water costs you efficiency, so cleaning is not housekeeping — it is fuel economy.** Shut the boiler down from the mains before starting.

<Callout type="error" title="Isolate and cool first">
  On all repair, maintenance and cleaning work, shut down the boiler from the mains. Let the boiler
  cool before opening it up — opening doors on a hot boiler causes burns and can damage the lining.
</Callout>

## The four surfaces [#the-four-surfaces]

<Steps>
  <Step>
    ### Ash — every day [#ash--every-day]

    **Remove the ash from the boiler daily.** The ash pan sits outside the unit at the front of the ash door.

    Ash banked against the grate blocks primary air and pushes the fire into smouldering — which is exactly the condition that tars the chimney.
  </Step>

  <Step>
    ### Furnace and loading chamber — weekly [#furnace-and-loading-chamber--weekly]

    **Clean and scrape the surface of the furnace and of the loading chamber.**

    Use the supplied scraper. Work the flat plate surfaces where the water jacket sits behind the steel — that is where deposits cost the most.
  </Step>

  <Step>
    ### Combustion air ducts — weekly [#combustion-air-ducts--weekly]

    **Clean the air ducts in the combustion chamber with a suitable tool.**

    These are the passages that deliver the air the fan is metering. Partly blocked ducts mean the controller's fan percentages no longer correspond to the air actually reaching the fire.
  </Step>

  <Step>
    ### Heat exchanger — weekly [#heat-exchanger--weekly]

    **Clean the top of the heat exchanger from soot using the brush.**

    Access is through the service flue gas door (callout 10 on the [structure drawing](https://uni.sonicar.tech/docs/start/how-it-works#the-combustion-path)). This is the third pass, where flue gas gives up its last useful heat before the chimney.
  </Step>
</Steps>

## Mid-winter [#mid-winter]

**We recommend boiler cleaning in mid-winter at least once a week.**

Deposits and gum formation by condensation depend on the fuel type — wood more than coal — the chimney draft and the operation mode. Deep winter combines the longest burns, the lowest return temperatures and the heaviest fuel use, so it fouls fastest.

## Tools [#tools]

| Tool                           | Use                                  |
| ------------------------------ | ------------------------------------ |
| Brush                          | Heat exchanger and flue passes       |
| Scraper                        | Furnace and loading chamber surfaces |
| Suitable duct tool             | Combustion air ducts                 |
| Ash shovel and metal container | Daily ash removal                    |
| Vacuum rated for ash           | Fine ash, once cold                  |

Brush and scraper are consumables and are not covered by warranty.

<Callout type="warn" title="Ash disposal">
  Ash can retain live embers for days. Store it in a metal container with a lid, on a
  non-combustible surface, away from the building.
</Callout>

## What clean looks like [#what-clean-looks-like]

**Clean means bare metal, not "less black."** After a weekly clean you should be able to:

* see the grate clearly with no banked ash;
* feel plate metal, not a crust, on the chamber walls;
* see daylight down the air ducts;
* and pull a brush through the heat exchanger without resistance.

If the boiler is not reaching setpoint on a full load of dry wood, the heat exchanger is the first thing to check.

<NextStep href="/docs/maintenance/chimney-care" title="Chimney care">
  Sweeping frequency, condensation, and why the joints fail first.
</NextStep>


# Parts and service (/docs/maintenance/parts-service)



**Two service jobs are safely owner-serviceable — the fuse and the temperature sensors — and everything else on a boiler under warranty belongs with an accredited service centre.**

<Callout type="error" title="Isolate first">
  Before performing any repair work, be sure to disconnect the regulator plug from the 230 V power
  supply.
</Callout>

## Fuse replacement [#fuse-replacement]

**If the fuse blows, replace it only with a new one of the same rating.** The fuse holder is on the control unit motherboard, at the back of the regulator housing.

<Figure src="/img/controller/fuse.jpg" alt="A 5 by 20 millimetre glass cartridge fuse" caption="<><b>Figure 7 — the fuse.</b> 250 V, 3.15 A, 5 × 20 mm.</>" source="TIS Tronic 260U manual §7.4" width="708" height="279" max="380" />

| Property | Value  |
| -------- | ------ |
| Voltage  | 250 V  |
| Current  | 3.15 A |
| Diameter | 5 mm   |
| Height   | 20 mm  |

<Callout type="warn" title="Fuse failure is not covered by warranty">
  A fuse that blows repeatedly is a symptom, not the fault. Find the overload before fitting the
  third one.
</Callout>

## Sensor replacement [#sensor-replacement]

<Steps>
  <Step>
    ### Isolate [#isolate]

    Disconnect the power plug from the electrical outlet.
  </Step>

  <Step>
    ### Open the housing [#open-the-housing]

    Unscrew the fixing screws on the back of the housing, then remove the top cover.
  </Step>

  <Step>
    ### Find the socket [#find-the-socket]

    Use the [terminal map](https://uni.sonicar.tech/docs/controller/wiring-reference#terminal-map): `T1` boiler, `T2` HUW, `T3` exhaust, `I1` STB.
  </Step>

  <Step>
    ### Release the wire [#release-the-wire]

    Press the connector with a flat screwdriver to release the fastening clip, then disconnect the wire.
  </Step>

  <Step>
    ### Fit the replacement [#fit-the-replacement]

    **Sensors have no polarity** — wiring sequence is not significant. Correctly installed wires provide a reliable connection: it is impossible to disconnect the wire without pressing the terminal. If a wire pulls free, it is not seated.
  </Step>

  <Step>
    ### Refit the sensor in the boiler [#refit-the-sensor-in-the-boiler]

    The CH sensor goes into the immersion well, then the STB on top of it. &#x2A;*No liquid in the well.** The sensor must be installed in a dry place.
  </Step>
</Steps>

### Sensor part reference [#sensor-part-reference]

| Sensor             | Terminal | Wire length | Type                             |
| ------------------ | -------- | ----------- | -------------------------------- |
| CH sensor (boiler) | `T1`     | 0.8 m       | KTY-81-210                       |
| HUW                | `T2`     | 3 m         | KTY-81-210                       |
| Exhaust gases      | `T3`     | —           | PT1000 (not in the standard kit) |
| STB                | `I1`     | 1 m         | Bimetal                          |

Higher-temperature thermal protection is available as **DZT-2** (opens 200 °F / 95 °C, closes 155 °F / 70 °C), versus **DZT-1** (opens 185 °F / 85 °C, closes 140 °F / 60 °C). Order from MBtek under Parts — UNI 15-40-60-95.

## Consumables [#consumables]

**Not covered by warranty:**

* sealing cord (door gaskets)
* cast iron grate
* handles
* bolts and nuts
* brush and scraper
* controller fuse

## What must go to service [#what-must-go-to-service]

<Callout type="warn" title="Unauthorised repair voids the warranty">
  The controller can be connected and put into operation by an accredited representative. Unauthorised
  activation, making changes to the device, and repairs may cause deterioration of the boiler's
  operating parameters and its safety — and lead to loss of warranty for both the regulator and the
  boiler as a whole.
</Callout>

Warranty repairs can only be performed by a specialised organisation: the installer, service centre or distributor accredited by the manufacturer. Warranty repairs are free of charge.

Before a warranty repair, the equipment must be cleaned of soot, tar and other contaminants, and the customer must provide access and facilities to perform the work.

## Controller environment [#controller-environment]

**The controller must be kept from hard freezing, overheating, water, or a very high-humidity environment.**

If water or condensation enters the controller: disconnect immediately, dry using a hairdryer at a **low** temperature, wait **24 hours**, then reconnect.

## Disposal [#disposal]

The crossed-out wheeled bin symbol means the product must not be disposed of in regular waste bins. Return used equipment to a designated collection point for waste electrical and electronic equipment. Manufacturer environmental registration number: 000002627.

<SupportCta title="Need a part or a service visit?" />

<NextStep href="/docs/troubleshooting/common-problems" title="Troubleshooting">
  Symptom-first diagnosis for the faults that actually happen.
</NextStep>


# Maintenance schedule (/docs/maintenance/schedule)



**Soot and ash deposits on the walls reduce heat transfer and efficiency — everything in this schedule exists to prevent that, or to catch a fault before it becomes a failure.** Shut the boiler down from the mains before any repair, maintenance or cleaning.

## The schedule [#the-schedule]

| Frequency                         | Task                                                                                           |
| --------------------------------- | ---------------------------------------------------------------------------------------------- |
| **Every day**                     | Remove ash from the boiler                                                                     |
| **Every day**                     | Check the external state of the boiler body, the controller, sensors and wiring; clean of dust |
| **Every day**                     | Check system pressure                                                                          |
| **Weekly**                        | Clean and scrape the surface of the furnace and the loading chamber                            |
| **Weekly**                        | Clean the air ducts in the combustion chamber with a suitable tool                             |
| **Weekly**                        | Brush the top of the heat exchanger clear of soot                                              |
| **At least weekly in mid-winter** | Full boiler cleaning                                                                           |
| **Regularly**                     | Inspect and clean the chimney                                                                  |
| **Before the heating season**     | Check wire condition, regulator fastening; clean the controller of dust                        |
| **During the heating season**     | Repeat the electrical check                                                                    |
| **End of season**                 | Deep clean, chimney sweep, leave the system full, protect against frost                        |
| **Before any repair**             | Disconnect from the mains                                                                      |

<Callout title="Why weekly, and why mid-winter">
  Deposition depends on the fuel, the chimney draft and the operating mode. Wood deposits more than
  coal, and a boiler running long and cool in deep winter deposits most of all. That is exactly when
  the cleaning interval needs to be shortest.
</Callout>

## Who may do the work [#who-may-do-the-work]

**For maintenance and operation of the boiler, a person familiar with the device and the rules of operation of this type of equipment is allowed.**

Warranty repairs can only be performed by a specialised organisation — the installer, service centre or distributor accredited by the manufacturer. At the time of performing a warranty repair, the equipment must be cleaned of soot, tar and other contaminants, and the customer undertakes to provide all facilities and access.

## Checks that catch problems early [#checks-that-catch-problems-early]

<Accordions>
  <Accordion title="Electrical faults">
    If there is a fault in the electrical system — a short circuit to the boiler body, deterioration of wiring insulation, and so on — **immediately disconnect the boiler from the power supply** and call after-sales service for repair.
  </Accordion>

  <Accordion title="Draft">
    Check the availability of draft in the chimney by presenting a strip of paper to the ash pit. The paper strip should deviate to the side of the ash pit. Make sure the ventilation openings for inflow and exhaust have not been restricted or blocked.
  </Accordion>

  <Accordion title="System pressure">
    Throughout the heating season, monitor the pressure in the system. Air must be removed during the first weeks of operation.
  </Accordion>

  <Accordion title="Door gaskets">
    Sealing cord is a consumable and is not covered by warranty. A leaking door lets uncontrolled air in, which defeats the controller's air management.
  </Accordion>

  <Accordion title="Water quality">
    Scale reduces heat transfer by 10 % per millimetre and is not covered by warranty. If you have been topping up frequently, find the leak — repeated fresh fill water means repeated fresh hardness.
  </Accordion>
</Accordions>

## Consumables [#consumables]

**These parts wear and are explicitly not covered by warranty:**

* sealing cord (door gaskets)
* cast iron grate
* handles
* bolts and nuts
* brush and scraper
* controller fuse

Order replacements from MBtek — see [Contact](https://uni.sonicar.tech/docs/support/contact).

<NextStep href="/docs/maintenance/cleaning" title="Cleaning the boiler">
  How to clean each surface, and with what.
</NextStep>


# Commissioning checklist (/docs/installation/commissioning)



**Work through this list before lighting the first fire — and fill in the warranty card while you are at it, because an unsigned card can invalidate the warranty.** Commissioning must be performed by a professional authorised by the manufacturer.

## Hydraulic [#hydraulic]

<Accordions>
  <Accordion title="System filled with treated water below 2 ppm hardness">
    Hard water scales the heat transfer surfaces. 1 mm of scale costs 10 % of heat transfer, and scale damage is not covered by warranty. See [Filling and water quality](./filling.mdx).
  </Accordion>

  <Accordion title="Safety relief valve fitted and not isolatable">
    Mandatory. The discharge must be piped to a location where a release of boiling water is safe.
  </Accordion>

  <Accordion title="Expansion tank fitted and correctly charged">
    Required on both closed and open systems. Volume comes from the heating system design.
  </Accordion>

  <Accordion title="Return-temperature protection in place">
    Thermostatic valve holding the return above roughly 130 °F. Without a thermostatic valve on direct circulation with a return below 122 °F, set the supply to at least 149 °F.
  </Accordion>

  <Accordion title="System pressure-tested and vented">
    Maximum test pressure 50 psi. Working pressure must not exceed 15 psi. Expect to vent repeatedly over the first weeks.
  </Accordion>

  <Accordion title="Flow bypass present">
    So the pumps always have a path when the controller forces them on above the boiler cooling temperature.
  </Accordion>
</Accordions>

## Electrical [#electrical]

<Accordions>
  <Accordion title="Boiler electrically grounded">
    Boilers TIS UNI must be electrically grounded.
  </Accordion>

  <Accordion title="Ground and insulation resistance measured">
    Measure the ground resistance of pump motors and the insulation resistance of the wiring before starting the controller.
  </Accordion>

  <Accordion title="Voltage stabiliser installed">
    Recommended for reliable and stable regulator operation.
  </Accordion>

  <Accordion title="Boiler sensor in the immersion well, STB on top of it">
    No liquid in the well. See [Electrical and sensors](./electrical.mdx).
  </Accordion>

  <Accordion title="STB verified on I1">
    The fan must cut above \~90 °C, and must not restart until water is below 60 °C and the alarm has been manually reset.
  </Accordion>

  <Accordion title="Room thermostat contact logic checked">
    Dry contact on I2: open when satisfied, closed on demand. 24 VAC thermostats need an SPDT relay.
  </Accordion>

  <Accordion title="Pump relay wired correctly for 120 V circulators">
    Relay coil on contacts 7 and 8; pump on 3 and 5, or 4 and 6. See [Pump wiring](./pump-wiring.mdx).
  </Accordion>
</Accordions>

## Flue and room [#flue-and-room]

<Accordions>
  <Accordion title="8 in acid-resistant stainless chimney, insulated where exposed">
    Never smaller than the boiler flue outlet. Minimum bends.
  </Accordion>

  <Accordion title="Draft verified">
    Hold a paper strip at the ash pit — it should deviate towards the ash pit.
  </Accordion>

  <Accordion title="Ventilation openings clear">
    Inflow and exhaust openings not restricted or blocked.
  </Accordion>

  <Accordion title="Clearances confirmed against local code">
    24 in back and sides, 36 in front, 28 in overhead, 12 in to combustibles (6 in for double-wall pipe), 6 in to non-combustibles. Document them for insurance.
  </Accordion>

  <Accordion title="Fuel stacked at least 4 ft from the boiler">
    And dry — aim for 20 % moisture or below.
  </Accordion>
</Accordions>

## Controller [#controller]

<Accordions>
  <Accordion title="MBtek recommended settings loaded">
    The factory defaults are generic. Load the UNI 60 values from [Recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings) before the first burn.
  </Accordion>

  <Accordion title="Fan type set to WPA 07 / DM85">
    Selecting the wrong fan type leaves a dead band where speed changes do nothing.
  </Accordion>

  <Accordion title="Exhaust gas sensor activated if fitted">
    Required for Brager Expert exhaust gases mode. The PT1000 is not in the standard kit.
  </Accordion>

  <Accordion title="Hot water module configured or deliberately left off">
    Summer, Winter or Off — see [Hot water](https://uni.sonicar.tech/docs/controller/hot-water).
  </Accordion>

  <Accordion title="Software version noted">
    Recorded from the controller menu, for future support calls.
  </Accordion>
</Accordions>

## Documentation [#documentation]

<Accordions>
  <Accordion title="Warranty card completed with the commissioning date">
    Warranty is only valid with a properly filled warranty card showing the date of commissioning by the qualified installer. Demand that your distributor and commissioning professional fill it in correctly.
  </Accordion>

  <Accordion title="Clearance distances and code compliance recorded">
    Keep the documentation for insurance and reference purposes.
  </Accordion>

  <Accordion title="Owner trained">
    Loading, ash removal, the weekly clean, the alarm list and the emergency procedure.
  </Accordion>
</Accordions>

<Callout type="warn" title="Do not walk away from the first fires">
  Do not leave the boiler in operation without supervision during the first firings after
  installation.
</Callout>

<SupportCta title="Commissioning support" />

<NextStep href="/docs/controller/overview" title="TIS Tronic 260U overview">
  Now set up the controller before you light it.
</NextStep>


# Mounting the controller (/docs/installation/controller-mounting)



**The TIS Tronic 260U mounts into the boiler lid through an adapter plate, and replaces the older TIS Tronic 83 in five steps.** If your boiler shipped with the 260U already fitted, skip to [First start](https://uni.sonicar.tech/docs/controller/first-start).

<Callout type="warn" title="Remove the old regulator first">
  Before installing the TIS Tronic 260U regulator, the previous TIS Tronic 83 regulator must be
  removed from the boiler **with its casing**.
</Callout>

This procedure applies to **TIS UNI** and **TIS HARD PLUS 150** boilers.

## Replacing a TIS Tronic 83 [#replacing-a-tis-tronic-83]

<Steps>
  <Step>
    ### Bend the adapter plate [#bend-the-adapter-plate]

    Bend the adapter plate (liner) up to a **90° angle**.

    <Figure src="/img/swap/step1.jpg" alt="Sheet-metal adapter liner bent to a 90 degree angle, with four fixing tabs at its corners" caption="Step 1 — the adapter plate (liner) bent up to 90°. The four corner tabs are folded over in step 3." source="TIS Tronic 260U replacement guide" width="388" height="284" max="360" />
  </Step>

  <Step>
    ### Place the liner inside the lid [#place-the-liner-inside-the-lid]

    Place the bent liner inside the lid of the boiler.

    <Figure src="/img/swap/step2.jpg" alt="Boiler lid seen from underneath with the bent adapter liner positioned in the controller aperture" caption="Step 2 — the bent liner positioned inside the boiler lid." source="TIS Tronic 260U replacement guide" width="600" height="400" max="440" />
  </Step>

  <Step>
    ### Fix the liner [#fix-the-liner]

    Fix the liner on the cover by bending the **four protrusions** of the liner up through 180°.

    <Figure src="/img/swap/step3.jpg" alt="Boiler lid with the controller aperture formed by the fitted liner" caption="Step 3 — the liner fixed, leaving the controller aperture in the lid." source="TIS Tronic 260U replacement guide" width="539" height="353" max="420" />

    <Figure src="/img/swap/step3b.jpg" alt="Close-up of the liner in the lid with its four protrusions bent over to lock it in place" caption="Close-up — the four protrusions bent through 180° to lock the liner to the cover." source="TIS Tronic 260U replacement guide" width="290" height="200" max="360" />
  </Step>

  <Step>
    ### Set the regulator body in the lid [#set-the-regulator-body-in-the-lid]

    Set the body of the regulator on the lid of the boiler.

    <Figure src="/img/swap/step4.jpg" alt="Boiler lid with the controller aperture prepared and the regulator body seated" caption="Step 4 — the regulator body seated on the boiler lid." source="TIS Tronic 260U replacement guide" width="710" height="369" max="480" />
  </Step>

  <Step>
    ### Screw down the control panel [#screw-down-the-control-panel]

    Screw in the **two screws** and mount the control panel of the regulator on the boiler's lid.

    <Figure src="/img/swap/step5.jpg" alt="Controller front panel fitted into the boiler lid" caption="Step 5 — control panel mounted on the boiler lid." source="TIS Tronic 260U replacement guide" width="564" height="374" max="440" />

    <Figure src="/img/swap/step5b.jpg" alt="Close-up of the mounted controller panel seated in the lid aperture" caption="Close-up of the finished installation." source="TIS Tronic 260U replacement guide" width="199" height="214" max="320" />
  </Step>
</Steps>

## After mounting [#after-mounting]

<Steps>
  <Step>
    ### Reconnect the sensors and outputs [#reconnect-the-sensors-and-outputs]

    Work through the [terminal map](https://uni.sonicar.tech/docs/installation/electrical#terminal-map): fan on `Q1`, pumps on `Q3` / `Q4`, STB on `I1`, thermostat on `I2`, sensors on `T1` / `T2` / `T3`.
  </Step>

  <Step>
    ### Check the panel ribbon [#check-the-panel-ribbon]

    The front panel connects to the board at `TR2_DISP`. A blank screen after a swap is very often this connector.
  </Step>

  <Step>
    ### Power up and verify [#power-up-and-verify]

    Switch on using the switch on the back panel. A welcome screen should appear, followed by a main screen, with the yellow **STOP** light constantly illuminated.
  </Step>
</Steps>

<Callout type="warn" title="Warranty note">
  The controller may be connected and put into operation by an accredited representative. Unauthorised
  activation, changes to the device or repairs may degrade the boiler's operating parameters and
  safety, and lead to loss of warranty for both the regulator and the boiler as a whole.
</Callout>

## Protect it from the environment [#protect-it-from-the-environment]

**The controller must be kept from hard freezing, overheating, water, or a very high-humidity environment.**

If water or condensation gets inside: disconnect it immediately, dry it with a hairdryer at a **low** temperature, wait **24 hours**, then reconnect.

<NextStep href="/docs/installation/commissioning" title="Commissioning checklist">
  The final pre-fire walkthrough before you light the boiler.
</NextStep>


# Electrical and sensors (/docs/installation/electrical)



**All electrical work on the UNI 60 must be done by a qualified electrician, and the boiler must be electrically grounded.** The safety chain that protects the boiler from boiling is hardware, not software, so getting the STB right matters more than any controller setting.

<Callout type="error" title="Power off before any work">
  The device is under electric voltage. It is forbidden to work on connecting pumps, fans or other
  electrical devices while the regulator is connected to the power supply. Switch off the power and
  take measures against accidental switching on.
</Callout>

## Before energising [#before-energising]

<Steps>
  <Step>
    ### Ground the boiler [#ground-the-boiler]

    **Boilers TIS UNI must be electrically grounded.**
  </Step>

  <Step>
    ### Measure before you connect [#measure-before-you-connect]

    Measure the ground resistance of the electric motors (pumps), and the insulation resistance of the electrical wires.
  </Step>

  <Step>
    ### Fit a voltage stabiliser [#fit-a-voltage-stabiliser]

    For reliable and stable operation of the regulator, install a voltage stabiliser with an appropriate load rating.
  </Step>

  <Step>
    ### Check the environment [#check-the-environment]

    The controller must not be exposed to liquids and must not be located in rooms with high humidity. Keep dirt and conductive dust out of it. Operating range: **5–40 °C**, **30–75 % RH**.
  </Step>
</Steps>

## Terminal map [#terminal-map]

<Figure src="/img/install/board-diagram.jpg" alt="TIS Tronic 260U board layout showing the 230 V power input, PE terminals, fan output Q1, pump outputs Q3 and Q4, inputs I1 and I2, sensor terminals T1, T2, T3, the X23 alarm header and the TR2_DISP panel connector" caption="<><b>TIS Tronic 260U board view and connection diagram.</b></>" source="TIS Tronic 260U manual §7.1" width="1324" height="1050" max="620" />

| Symbol     | Designation                             |
| ---------- | --------------------------------------- |
| `Q1`       | Fan outlet                              |
| `Q3`       | Central heating pump outlet             |
| `Q4`       | Hot water (HUW) pump output             |
| `I1`       | Emergency thermostat STB                |
| `I2`       | Central heating room thermostat         |
| `T1`       | Boiler temperature sensor               |
| `T2`       | HUW temperature sensor                  |
| `T3`       | Exhaust gas temperature sensor          |
| `TR2_DISP` | Panel connector                         |
| `X23`      | Additional alarm (optional)             |
| `- + A B`  | Alternative slot for additional modules |

Power comes in at **230 V** on `L` and `N`, with `PE` earth terminals on the board.

## Sensor placement [#sensor-placement]

<Figure src="/img/install/sensor-placement.jpg" alt="Diagram showing the T1 boiler sensor lowered into the immersion well on the boiler top plate, with the STB or DZT thermal protection sensor mounted beside it" caption="<><b>Sensor placement.</b> T1 (boiler sensor) goes down into the immersion well; the STB/DZT thermal protection sensor sits on the same well.</>" source="UNI Install Guide, page 2" width="378" height="277" max="420" />

**The CH sensor is lowered into the immersion well, followed by the thermal protection sensor (STB).**

<Callout type="warn" title="No liquid in the well">
  Adding any liquid to the immersion well is forbidden — no oil, no water, no paste. The sensor
  should be installed in a dry place.
</Callout>

If there is no immersion well, it is permitted to install the CH sensor on the supply branch pipe — up to the connection nut — and press it against the pipe with a metal clamp.

## Sensor schedule [#sensor-schedule]

| Sensor               | Terminal | Wire length | Type       |
| -------------------- | -------- | ----------- | ---------- |
| CH sensor (boiler)   | `T1`     | 0.8 m       | KTY-81-210 |
| HUW (hot water tank) | `T2`     | 3 m         | KTY-81-210 |
| Exhaust gases        | `T3`     | —           | PT1000     |
| STB                  | `I1`     | 1 m         | Bimetal    |

**Sensors have no polarity** — wiring sequence is not significant.

<Callout type="warn" title="The exhaust sensor is not included">
  The PT1000 exhaust gas sensor is not supplied in the regulator standard kit. It is required for
  *Brager Expert exhaust gases* mode, which is the mode MBtek recommends for the UNI 60.
</Callout>

## The STB safety chain [#the-stb-safety-chain]

<Figure src="/img/controller/hydraulic-stb.jpg" alt="Recommended hydraulic diagram showing the boiler with fan, STB and CH sensor, central heating pump, thermostatic three-way valve, check valves, heating system radiators, HUW pump and water tank, with a detail of the sensor immersion well" caption="<><b>STB connection options and the recommended hydraulic circuit.</b> Note the detail panel: the CH sensor goes into the immersion well first, then the STB. The diagram is approximate and simplified.</>" source="TIS Tronic 260U manual §7.3" width="745" height="427" />

**An independent bimetallic sensor turns off the fan if the water temperature in the boiler rises above 90 °C**, preventing the water from boiling in the event of boiler overheating.

In accordance with **PN-EN 303-5:2012**, when the water temperature drops back to a safe value it is **not** possible for the fan to turn itself on again. The fan can only restart after:

1. the water temperature in the boiler drops below **60 °C**, and
2. the error is **manually reset** on the control panel.

The protection sensor has two wires, connected to the `I1` STB terminal. Polarity does not matter.

### DZT thermal protection sensors [#dzt-thermal-protection-sensors]

| Sensor | Opens at       | Closes at      |
| ------ | -------------- | -------------- |
| DZT-1  | 185 °F / 85 °C | 140 °F / 60 °C |
| DZT-2  | 200 °F / 95 °C | 155 °F / 70 °C |

Both connect to terminal `I1`. To operate at a higher temperature, order a DZT-2 from MBtek (Parts — UNI 15-40-60-95).

## Replacing a sensor [#replacing-a-sensor]

<Steps>
  <Step>
    Disconnect the power plug from the electrical outlet.
  </Step>

  <Step>
    Unscrew the fixing screws on the back of the housing and remove the top cover.
  </Step>

  <Step>
    Find the socket on the board using the terminal map above.
  </Step>

  <Step>
    Press the connector with a flat screwdriver to release the fastening clip, then withdraw the wire.
  </Step>

  <Step>
    Fit the new sensor. Correctly installed wires cannot be pulled out without pressing the terminal — if a wire slides free, it is not seated.
  </Step>
</Steps>

<NextStep href="/docs/installation/pump-wiring" title="Pump wiring">
  Connecting a 120 V circulator to the controller's 230 V outputs.
</NextStep>


# Filling and water quality (/docs/installation/filling)



**Fill the boiler with clean, transparent water of no more than 2 ppm hardness — scale damage is explicitly excluded from the warranty.** This is the cheapest step in the whole installation to get right and one of the most expensive to get wrong.

<Callout type="error" title="Never fire a dry or frozen boiler">
  Do not start the boiler in the absence of water, or if the water in it is frozen. Do not operate
  the boiler without water or only partially filled.
</Callout>

## Water quality [#water-quality]

**When filling the heating system with water, check that it is clean and transparent, without impurities or aggressive substances, with hardness of not more than 2 ppm.**

Hard water causes scale on the heat transfer surfaces, which:

* reduces heat exchange and therefore efficiency;
* can cause premature failure of the boiler.

**1 mm of scale deposit reduces heat transfer from the metal to the water by 10 %.**

If the water hardness does not meet the required parameters, the water should be **treated** before filling.

<Callout type="warn" title="Not covered by warranty">
  Damage to the boiler due to the formation of scale is not covered by warranty.
</Callout>

## Filling procedure [#filling-procedure]

<Steps>
  <Step>
    ### Check ambient temperature [#check-ambient-temperature]

    Do not leave the boiler with water in it at an ambient temperature below **+41 °F / +5 °C**. If the room can freeze, do not fill until that is resolved.
  </Step>

  <Step>
    ### Test and treat the fill water [#test-and-treat-the-fill-water]

    Measure hardness. Treat if it is above 2 ppm.
  </Step>

  <Step>
    ### Fill slowly from the lowest point [#fill-slowly-from-the-lowest-point]

    Filling from the bottom pushes air up and out rather than trapping it in the emitters.
  </Step>

  <Step>
    ### Fill to working pressure [#fill-to-working-pressure]

    Fill at a pressure not exceeding the maximum working boiler pressure. Normal operating pressure must not exceed **15 psi**.
  </Step>

  <Step>
    ### Vent every high point [#vent-every-high-point]

    Work through the automatic and manual vents, the emitters and the boiler itself.
  </Step>

  <Step>
    ### Pressure-test [#pressure-test]

    Maximum test pressure is **50 psi**. Hold and inspect every joint, then release to working pressure.
  </Step>

  <Step>
    ### Check the relief valve discharge [#check-the-relief-valve-discharge]

    Confirm the discharge is piped to a safe location and is not obstructed or valved.
  </Step>
</Steps>

## Air in the first weeks [#air-in-the-first-weeks]

**Air must be removed during the first weeks of operation.** Dissolved air comes out of solution as the system heats for the first time, and it collects at the high points.

Throughout the heating season, monitor the pressure in the system — a falling pressure means a leak or a failing expansion tank; a rising pressure with heat means the expansion tank is undersized, waterlogged, or the fill valve is passing.

## Quick reference [#quick-reference]

| Parameter                           | Value               |
| ----------------------------------- | ------------------- |
| Maximum water hardness              | 2 ppm               |
| Effect of 1 mm scale                | −10 % heat transfer |
| Maximum operating pressure          | 15 psi              |
| Never exceed                        | 36 psi              |
| Maximum test pressure               | 50 psi              |
| Maximum water temperature           | 185 °F / 85 °C      |
| Minimum ambient temperature, filled | +41 °F / +5 °C      |

<NextStep href="/docs/installation/electrical" title="Electrical and sensors">
  Power, grounding, the boiler sensor, the STB safety chain and the exhaust probe.
</NextStep>


# Hydronic piping (/docs/installation/piping)



**Pipe the boiler with 2 in supply and return, a safety relief valve that can never be isolated, an expansion tank, a drain, and return-temperature protection.** The relief valve and the return protection are the two items installers most often defer — and the two that cause the most expensive failures.

<Callout type="error" title="Relief valve is mandatory">
  Never use the appliance without a relief valve. Position the discharge drainage so that it is safe
  in case of opening — it discharges boiling water under pressure.
</Callout>

## Connection schedule [#connection-schedule]

| Connection    | Size | Notes                               |
| ------------- | ---- | ----------------------------------- |
| Supply (flow) | 2 in | Callout 11 on the structure drawing |
| Return        | 2 in | Callout 12                          |
| Drain         | —    | Callout 13, at the base             |
| Flue outlet   | 8 in | Callout 4                           |
| Sensor well   | —    | Callout 14, top of the boiler       |

## Required devices [#required-devices]

<Steps>
  <Step>
    ### Safety relief valve [#safety-relief-valve]

    Fit it on the boiler side of any isolating valve, so it can never be valved out. Run the discharge to a safe location.

    Maximum operating pressure is **15 psi**; maximum test pressure is **50 psi**; pressure must never be allowed above **36 psi**.
  </Step>

  <Step>
    ### Expansion tank [#expansion-tank]

    An open or membrane expansion tank is required on both closed and open systems. Size it from the heating volume as part of the system design.
  </Step>

  <Step>
    ### Return-temperature protection [#return-temperature-protection]

    Fit a thermostatic valve that holds the return above roughly **130 °F**.

    **A boiler protection valve is mandatory if the system operates below 140 °F.**

    If you use direct circulation **without** a thermostatic valve and the return falls below **122 °F**, the supply must be set to at least **149 °F** to avoid condensation.
  </Step>

  <Step>
    ### Check valve on make-up [#check-valve-on-make-up]

    If using automatic make-up water, install a check valve according to local regulations. Fill at a pressure not exceeding the maximum working boiler pressure.
  </Step>

  <Step>
    ### Flow bypass [#flow-bypass]

    Include a bypass so the pumps always have a path, even when every zone actuator is closed. The controller forces all pumps on above the boiler cooling temperature.
  </Step>
</Steps>

## Why return protection matters [#why-return-protection-matters]

<Figure src="/img/install/note-protection-valve.jpg" alt="Note from the UNI install guide: the use of a boiler protection valve is a must if using below 140 degrees Fahrenheit, because return water can generate heavy condensation on the unit giving the impression of a water leak" caption="<><b>MBtek install-guide note.</b> Condensation from a cold return is routinely mistaken for a leaking boiler.</>" source="UNI Install Guide, page 1" width="590" height="378" max="480" />

**Cold return water condenses acidic moisture and tar onto the inside of the firebox and heat exchanger.** That does three things, all bad:

1. It corrodes the steel body from the inside.
2. It glues soot and tar to the heat transfer surfaces, cutting efficiency.
3. It pushes more tar into the chimney, increasing sweeping frequency and fire risk.

MBtek sells an all-in-one **boiler station** — pump, thermostatic valve and thermometer in one insulated assembly — and a standalone thermostatic **boiler protection valve** for this purpose.

<Figure src="/img/boiler/install-scheme.png" alt="Recommended installation scheme with the boiler station between the boiler and the buffer tank" caption="<><b>The boiler station sits on the return</b>, between the boiler and the rest of the system.</>" source="UNI Boiler Manual §8.1" width="1500" height="1622" />

## Natural circulation layouts [#natural-circulation-layouts]

**If the system circulates by gravity, place the return water pipe below the radiator.** Without that height difference the system will not move water.

## Pipe for maintenance [#pipe-for-maintenance]

* Fit isolating valves so the boiler can be drained without emptying the building.
* Leave the sensor well accessible — the boiler sensor and STB both live there.
* Keep the front 36 in and one side 16 in clear of pipework so the boiler can be brushed out.

<NextStep href="/docs/installation/filling" title="Filling and water quality">
  Water hardness limits, venting, and the pressure test.
</NextStep>


# Positioning the boiler (/docs/installation/positioning)



**Set the boiler in its final position, level, on a non-combustible floor, with the clearances already marked out — everything after this step is much harder to correct.** The UNI 60 weighs 1,224 lb and must stay upright the whole way in.

<Callout type="warn" title="Qualified trades only">
  The boiler must be connected according to a project developed by a specialist in hydronic heating
  systems, with the requisite qualification and experience. Electrical work requires a qualified
  electrician.
</Callout>

## Before you move it [#before-you-move-it]

<Steps>
  <Step>
    ### Confirm the room is ready [#confirm-the-room-is-ready]

    Clearances marked, floor rated and level, ventilation openings clear, chimney installed or at least positioned. See [Boiler room and clearances](https://uni.sonicar.tech/docs/planning/boiler-room).
  </Step>

  <Step>
    ### Complete the delivery inspection [#complete-the-delivery-inspection]

    Damage and missing items must be recorded before the delivery is accepted. See [What's in the box](https://uni.sonicar.tech/docs/start/whats-in-the-box).
  </Step>

  <Step>
    ### Check the route [#check-the-route]

    30 in wide, 36 in deep, 65 in tall, ±5 %. Doorways, corners, stair widths and floor protection along the whole route.
  </Step>
</Steps>

## Setting the boiler [#setting-the-boiler]

<Steps>
  <Step>
    ### Keep it vertical [#keep-it-vertical]

    Transport and handling must keep the boiler **in the vertical position only**. Loading and securing must ensure complete safety against mechanical damage.
  </Step>

  <Step>
    ### Position on a non-combustible floor [#position-on-a-non-combustible-floor]

    Set the boiler on its supports on a level, load-rated, non-combustible floor.
  </Step>

  <Step>
    ### Level it, then check the rear incline [#level-it-then-check-the-rear-incline]

    Level the body. The clearance drawing calls for a &#x2A;*minimum incline of 3°** at the back wall reference — this is the allowance for the flue connection run, not a tilt of the boiler itself.
  </Step>

  <Step>
    ### Verify final clearances [#verify-final-clearances]

    With the boiler in place, re-measure: 24 in back and sides, 36 in front, 28 in overhead, 12 in to combustibles.
  </Step>

  <Step>
    ### Fit the ash pan [#fit-the-ash-pan]

    The ash pan goes **outside the unit, at the front of the ash door** — not inside the boiler.
  </Step>
</Steps>

## Identify the connections [#identify-the-connections]

<Figure src="/img/boiler/structure.png" alt="Sectional drawing of the UNI boiler with numbered callouts for the supply and return pipe connections, drain pipe, temperature sensor well, fan and controller" caption="<><b>Locate these before piping:</b> 11 supply pipe connection, 12 return pipe connection, 13 drain pipe, 14 temperature sensor well, 4 chimney connection, 15 fan, 16 controller.</>" source="UNI Boiler Manual §6.0" width="1400" height="1153" />

| Callout | Connection              | UNI 60 size              |
| ------- | ----------------------- | ------------------------ |
| 11      | Supply pipe             | 2 in                     |
| 12      | Return pipe             | 2 in                     |
| 13      | Drain pipe              | —                        |
| 14      | Temperature sensor well | Boiler (CH) sensor + STB |
| 4       | Chimney connection      | 8 in                     |

## Connect the flue [#connect-the-flue]

<Steps>
  <Step>
    ### Match the diameter [#match-the-diameter]

    The chimney diameter must not be less than the diameter of the flue outlet — **8 in** for the UNI 60.
  </Step>

  <Step>
    ### Keep the run short and straight [#keep-the-run-short-and-straight]

    Use as few bends as possible. Each one costs draft.
  </Step>

  <Step>
    ### Respect the pipe clearance [#respect-the-pipe-clearance]

    **12 in** from the exhaust pipe to combustible material, or **6 in** for double-wall stove exhaust pipe.
  </Step>

  <Step>
    ### Seal and support [#seal-and-support]

    The connecting pipe must be supported independently of the boiler, and joints sealed. Acidic condensate attacks joints over time — see [Chimney care](https://uni.sonicar.tech/docs/maintenance/chimney-care).
  </Step>
</Steps>

<NextStep href="/docs/installation/piping" title="Hydronic piping">
  Supply, return, relief valve, drain and return-temperature protection.
</NextStep>


# Wiring a 120 V pump (/docs/installation/pump-wiring)



**Connect the supplied 220 VAC relay block to the controller on contacts 7 and 8, then wire the 120 V pump through contacts 3 and 5, or 4 and 6.** The controller's pump outputs switch 230 V; the relay block is what lets them control a North American circulator.

## Wiring diagram [#wiring-diagram]

<Figure src="/img/install/pump-110v-wiring.jpg" alt="Relay wiring diagram showing a circulator pump with ground, neutral and pump power leads, a 120 VAC outlet feeding contacts 5 and 6, pump power taken from contact 3, and the brown and blue 240 VAC coil leads from the controller output on contacts 7 and 8" caption="<><b>120 V pump through the 220 VAC relay block.</b> Contacts 7 and 8 take the 240 VAC coil feed from the controller output (UNI: CH3 / CH4). The pump's 120 VAC supply passes through contacts 3 and 5 (or 4 and 6).</>" source="UNI Install Guide, page 2" width="483" height="606" max="460" />

## Procedure [#procedure]

<Steps>
  <Step>
    ### Isolate [#isolate]

    Disconnect the controller from the mains. Take measures against accidental switching on.
  </Step>

  <Step>
    ### Wire the relay coil to the controller [#wire-the-relay-coil-to-the-controller]

    Connect the **220 V relay block** to the controller using **contacts 7 and 8**. This is the coil side — the controller's pump output switches it.

    The coil leads in the diagram are the **brown** and **blue** wires marked *240 VAC from controller output*.
  </Step>

  <Step>
    ### Wire the pump through the relay contacts [#wire-the-pump-through-the-relay-contacts]

    Connect the **120 V pump** to **contacts 3 and 5**, or **4 and 6**.

    In the diagram, the 120 VAC outlet feed lands on contact 5, and the pump power lead is taken from contact 3. Ground and neutral run directly from the outlet to the pump.
  </Step>

  <Step>
    ### Verify before closing up [#verify-before-closing-up]

    Check continuity and confirm no 230 V is present on the pump side. Only then restore power.
  </Step>
</Steps>

<Callout type="warn" title="Which controller output?">
  On UNI units the relay coil is fed from the controller's pump output — `Q3` for the central
  heating pump, `Q4` for the hot water pump. Each output is rated **1 A**. Check your circulator's
  inrush current against that limit.
</Callout>

## Output ratings [#output-ratings]

| Output | Device               | Rating |
| ------ | -------------------- | ------ |
| `Q1`   | Fan                  | 1 A    |
| `Q3`   | Central heating pump | 1 A    |
| `Q4`   | Hot water (HUW) pump | 1 A    |

The controller itself draws **4.5 W** with no external devices connected.

## When the pumps run [#when-the-pumps-run]

**Pumps do not follow the fan — they follow temperature.** Three settings govern them:

| Setting                    | MBtek value    | Effect                                                                                             |
| -------------------------- | -------------- | -------------------------------------------------------------------------------------------------- |
| Pump start temperature     | 35 °C / 95 °F  | All active pumps switch on above this boiler temperature. They switch off when it drops 5 °C below |
| Boiler cooling temperature | 78 °C / 172 °F | Above this, **all** circulation pumps in the heating system start, to shed heat                    |
| Maximum boiler temperature | 80 °C / 176 °F | External controls such as the room thermostat are ignored; fan control functions are disabled      |

There are also two quenching-related pump settings — whether the central heating pump stops when the fire goes out, and how long after. See [Quenching and fuel shortage](https://uni.sonicar.tech/docs/controller/quenching).

<NextStep href="/docs/installation/room-thermostat" title="Room thermostat">
  Wiring a dry-contact or 24 VAC thermostat to terminal I2.
</NextStep>


# Room thermostat (/docs/installation/room-thermostat)



**Connect the room thermostat to terminal `I2` as a dry contact — closed when the room is cold, open when it is up to temperature.** The controller uses it to start and stop the central heating circulation pump, not the fire.

| Thermostat type         | What to connect to `I2`                                                              |
| ----------------------- | ------------------------------------------------------------------------------------ |
| Dry-contact / volt-free | Connect the two contacts directly to `I2`                                            |
| 24 VAC                  | Drive a **24 VAC SPDT relay**, and take the relay's dry contacts to `I2`             |
| Line-voltage (120 V)    | Do **not** connect directly — interpose a relay so `I2` only ever sees a dry contact |

## Wiring [#wiring]

<Steps>
  <Step>
    ### Use a dry contact [#use-a-dry-contact]

    Connect to terminal `I2` with a **dry contact** — a volt-free switch, not a powered output.
  </Step>

  <Step>
    ### Interpose a relay for 24 VAC thermostats [#interpose-a-relay-for-24-vac-thermostats]

    If you are using a **24 VAC thermostat**, use a **24 VAC SPDT relay** so the controller sees a clean dry contact.
  </Step>

  <Step>
    ### Check the contact logic [#check-the-contact-logic]

    The thermostat must **disconnect** the contacts when the room temperature is reached, and **connect** them when the temperature is lower than the user's setpoint.
  </Step>
</Steps>

<Callout type="warn" title="Inverted logic breaks the control">
  For correct controller operation you need a thermostat that opens on satisfied and closes on
  demand. Many conventional heating thermostats do the opposite. Verify with a meter before
  commissioning.
</Callout>

## How the controller uses it [#how-the-controller-uses-it]

**When the room thermostat function is enabled, the circulation pump starts every time the room temperature falls below the thermostat setpoint (closed contact).**

When the room reaches the thermostat setpoint (open contact), the controller does not simply stop the pump — it **cycles** it, to keep the room temperature even:

| Parameter              | Range     | Factory default | Effect                                                                       |
| ---------------------- | --------- | --------------- | ---------------------------------------------------------------------------- |
| CH pump operating time | 30–250 s  | 30 s            | How long the pump runs during each cycle once the room is satisfied          |
| CH pump pause time     | 0–240 min | 1 min           | Gap between cycles. Set to **0** to disable the pump entirely when satisfied |

<Callout title="Overheat override">
  If the boiler temperature exceeds the **maximum boiler temperature** setting, room thermostat
  control is switched off to protect the boiler from overheating. The pump will run regardless of
  what the thermostat says.
</Callout>

## Wireless and remote options [#wireless-and-remote-options]

MBtek offers the **UNI Remote Control**, which connects compatible TIS controllers to Brager Connect for remote monitoring, alarms and adjustments. The recommended installation scheme also shows **Wi-Fi radiant thermostats**, one per zone, driving zone actuators on the PEX manifold rather than the boiler directly.

<NextStep href="/docs/installation/controller-mounting" title="Mounting the controller">
  Fitting the TIS Tronic 260U, including replacing an older TIS Tronic 83.
</NextStep>


# Boiler room and clearances (/docs/planning/boiler-room)



**Give the UNI 60 24 in to the back and sides, 36 in at the front, and 28 in overhead — then check that your local code does not demand more.** Clearances protect the building from the boiler and give you the room to clean it, which is the difference between a boiler that holds its efficiency and one that does not.

<Callout type="warn" title="Local codes take priority">
  All installations must comply with applicable local building codes. Clearance requirements for
  solid-fuel appliances and stove pipe vary by region — consult local regulations or a certified
  building inspector. Always verify requirements for your pipe type (single-wall or double-wall) and
  your installation location. Keep documentation of clearance distances and code compliance for
  insurance and reference.
</Callout>

## Required clearances [#required-clearances]

| Key | Reference                    | Required distance | Notes                                           |
| --- | ---------------------------- | ----------------- | ----------------------------------------------- |
| A   | Back wall to boiler          | 24 in             | Minimum incline of 3°                           |
| B   | Side wall to boiler (right)  | 24 in             | Minimum distance                                |
| C   | Side wall to boiler (left)   | 24 in             | Minimum distance                                |
| D   | Front of boiler              | 36 in             | Required distance for cleaning the boiler       |
| E   | Ceiling to boiler            | 28 in             | Minimum distance for cleaning the boiler        |
| F   | Combustible to exhaust pipe  | 12 in             | Minimum 6 in for double-wall stove exhaust pipe |
| G   | Combustibles to boiler       | 12 in             | Minimum distance                                |
| H   | Distance to non-combustibles | 6 in              | Minimum distance for non-combustibles           |

<Figure src="/img/boiler/clearance-side.png" alt="Side elevation of the UNI boiler in a masonry room showing clearance dimensions E to the ceiling, F from the flue pipe to combustibles, G from the boiler body and H from the lower casing" caption="<><b>Side view.</b> E is ceiling to boiler, F is combustible material to the exhaust pipe, G and H are the horizontal clearances from the boiler body.</>" source="UNI Boiler Manual, clearance addendum" width="1190" height="1144" max="620" />

<Figure src="/img/boiler/clearance-plan.png" alt="Plan view of the UNI boiler in a room showing clearance A to the back wall, B and C to the side walls and D in front of the boiler" caption="<><b>Plan view.</b> A is the back wall, B and C the side walls, D the working space in front of the loading and ash doors.</>" source="UNI Boiler Manual, clearance addendum" width="918" height="946" max="520" />

## Service access [#service-access]

**The clearance table is the safety minimum; the factory manual adds a separate service-space requirement.** Section 7.2 of the boiler manual asks for:

* **Frontage: minimum 4 ft.** You need this to pull ash, swing a brush and service the doors.
* **Rear wall: minimum 2 in** of physical gap to the casing.
* **One side: at least 16 in** of room to reach the back of the boiler.

Where the two sets of figures differ, build to the larger one. In practice that means **4 ft in front and 24 in all around**, which also satisfies the 24 in wall clearances.

## Room requirements [#room-requirements]

<Steps>
  <Step>
    ### Indoors only [#indoors-only]

    The boiler is designed for temperate and cold climatic zones and **must be installed indoors** with natural or forced draft.
  </Step>

  <Step>
    ### Non-combustible floor, level and load-rated [#non-combustible-floor-level-and-load-rated]

    The UNI 60 weighs **1,224 lb** dry and considerably more when full of water and fuel. Check the floor can carry it, and set it level — the manual asks for a minimum 3° incline allowance at the rear for the flue connection.
  </Step>

  <Step>
    ### Ventilation openings [#ventilation-openings]

    Make sure ventilation openings for inflow and exhaust air are present and have not been restricted or blocked. A forced-draft boiler needs combustion air; a sealed room will starve it and push smoke into the building.
  </Step>

  <Step>
    ### Fuel kept back [#fuel-kept-back]

    Do not stack fuel closer than **4 ft** to the boiler.
  </Step>

  <Step>
    ### Frost protection [#frost-protection]

    Do not leave the boiler filled with water at an ambient temperature below **+41 °F / +5 °C**. An unheated outbuilding in winter is a burst boiler waiting to happen.
  </Step>
</Steps>

## Getting the boiler into the room [#getting-the-boiler-into-the-room]

**Measure the route before the truck arrives.** The UNI 60 is 30 in wide, 36 in deep and 65 in tall, and must be transported and handled upright.

* Check door widths, corners, stair widths and ceiling heights along the whole route.
* Confirm you have lifting equipment rated well above 1,224 lb.
* Allow ±5 % on all published dimensions.

## Fire safety of surrounding materials [#fire-safety-of-surrounding-materials]

**Fire safety ratings are assigned by flame spread index under ASTM E84 and E119:**

| Class   | Flame spread index | Fire resistance |
| ------- | ------------------ | --------------- |
| Class A | 0–25               | Highest         |
| Class B | 26–75              | Moderate        |
| Class C | 76–200             | Lowest          |

The boiler's own materials are Class A: 1½ in mineral wool insulation is Class A1, and the ¼ in EN 10051/10 mild steel body is Class A (subject to individual material tests). Choose surrounding wall and floor protection materials with this in mind.

<NextStep href="/docs/planning/chimney" title="Chimney requirements">
  Flue diameter, material, insulation and the standards the chimney must meet.
</NextStep>


# Buffer tank and hot water (/docs/planning/buffer-and-hot-water)



**A UNI 60 running without thermal storage spends most of its time in supervision mode, cycling the fan to stop the water boiling — which wastes fuel and tars the chimney.** A buffer tank turns the boiler's natural behaviour, a hot fast burn, into something the building can use over the following hours.

## Why storage [#why-storage]

**A full 58-gallon firebox releases far more energy than a house absorbs at that moment.** Without somewhere to put it, the boiler:

* reaches setpoint quickly and drops into supervision;
* burns at low air for hours, which is exactly the condition that deposits tar;
* cycles the pumps and the fan repeatedly;
* and delivers uneven comfort at the emitters.

With a buffer tank, the boiler runs a clean, hot burn into storage, and the emitters draw from storage afterwards.

<Figure src="/img/boiler/install-scheme.png" alt="Installation scheme showing the buffer tank between the boiler station and the PEX manifold, with a flow bypass and expansion tank" caption="<><b>The buffer tank sits between the boiler and the distribution manifold</b>, with the flow bypass downstream of it.</>" source="UNI Boiler Manual §8.1" width="1500" height="1622" />

## Sizing [#sizing]

**Size storage from the firebox, not from the building.** The practical rule for gasification boilers is to store the output of one full load so the boiler can finish its burn without being throttled.

Factors that change the number:

* Firebox volume — **58 gal** on the UNI 60.
* Fuel density: oak stores far more energy per load than spruce. See [Fuel properties](https://uni.sonicar.tech/docs/operation/fuel).
* The temperature spread you can use between the top of the tank and your emitters. Radiant floor loops draw a wider spread than fan coils.
* Whether the tank also serves domestic hot water.

The MBtek recommended scheme uses a **BF650** buffer tank with a **DHW250** hot water tank; the UNI 60 product page pairs the boiler with the APOLLO **DHW80** combined buffer and indirect tank for smaller loads. Confirm the sizing with MBtek or your heating designer against a real heat-loss calculation.

## Domestic hot water on the controller [#domestic-hot-water-on-the-controller]

**The TIS Tronic 260U drives a dedicated hot water pump on output `Q4`, reading tank temperature from sensor `T2`.** The module is off until you switch it into Summer or Winter mode.

| Mode       | Behaviour                                                                                                                                                                        |
| ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Off**    | Hot water pump disabled; the home screen for hot water is greyed out                                                                                                             |
| **Summer** | The boiler's job is to make hot water only. All other pumps are switched off — except when the boiler exceeds the maximum boiler temperature, when all pumps start to protect it |
| **Winter** | Central heating pumps and the hot water pump operate together                                                                                                                    |

Full configuration is on the [hot water](https://uni.sonicar.tech/docs/controller/hot-water) page, including hysteresis, priority, working hours and the temperature-increase function.

<Callout title="Priority explained simply">
  With **HUW priority** on, the central heating pump stops while the tank is being heated, and the
  tank's temperature target outranks the boiler setpoint. It is the right choice when the household
  runs out of hot water; it is the wrong choice in deep winter if it lets the house cool.
</Callout>

## The sensor well [#the-sensor-well]

**The boiler (CH) sensor goes into the immersion well, and the STB goes on top of it.** Adding any liquid — oil, water, thermal paste — to the immersion well is forbidden.

Where no well is available, the CH sensor may be fitted to the supply branch pipe up to the connection nut and pressed against it with a metal clamp.

<NextStep href="/docs/planning/fuel-storage" title="Fuel and storage">
  How much wood you need, how dry it must be, and where to keep it.
</NextStep>


# Chimney requirements (/docs/planning/chimney)



**The UNI 60 needs an 8 in chimney in acid-resistant 316 stainless steel, and the flue must never be narrower than the boiler's outlet.** Draft is what makes a solid-fuel boiler work; an undersized or cold chimney will smoke into the room, tar up quickly and lose you efficiency.

## Specification [#specification]

| Requirement                          | Value                                                                                                          |
| ------------------------------------ | -------------------------------------------------------------------------------------------------------------- |
| Minimum diameter                     | 8 in — never less than the boiler flue outlet                                                                  |
| Material                             | Stainless steel 316, acid-resistant                                                                            |
| Construction, inside a brick channel | Single wall                                                                                                    |
| Construction, exposed                | Double-walled (insulated)                                                                                      |
| Standards                            | EN 1856-1:2013 part 1 (metal chimney requirements) · EN 1856-2:2013 part 2 (metal liners and connecting pipes) |
| Clearance to combustibles            | 12 in, or 6 in for double-wall stove exhaust pipe                                                              |

<Callout type="warn" title="Acid resistance is not optional">
  Flue gas from wood produces soot and condensation, and the condensate is acidic. Ordinary steel
  liners deteriorate at the joints. This is the single most common cause of premature chimney
  failure on wood boilers.
</Callout>

## Design rules [#design-rules]

<Steps>
  <Step>
    ### Keep the inside smooth [#keep-the-inside-smooth]

    The inside of the chimney should be smooth, with no condensation or soot deposit zones, so that draft is optimal and unobstructed.
  </Step>

  <Step>
    ### Minimise bends [#minimise-bends]

    The number of chimney bends should be as **small as possible**. Every bend costs draft and creates a place for deposits to collect.
  </Step>

  <Step>
    ### Insulate exposed runs [#insulate-exposed-runs]

    An exposed, uninsulated chimney runs cold, which drops draft and dramatically increases tar and condensation. Use double-walled insulated pipe outside heated space.
  </Step>

  <Step>
    ### Plan for cleaning [#plan-for-cleaning]

    Choose a chimney system that is easy to assemble and disassemble for maintenance, and that complies with fire safety standards. You will be sweeping it regularly — see [Chimney care](https://uni.sonicar.tech/docs/maintenance/chimney-care).
  </Step>
</Steps>

## Deposition rate [#deposition-rate]

**How fast your chimney fouls depends on the fuel and the boiler temperature.**

* **Wood deposits more than coal.** Tar and soot build faster on wood-fired units.
* **Low boiler temperatures deposit more.** Running cool, especially with a cold return, condenses tar out of the flue gas. This is the reason return-temperature protection matters — see [System design](https://uni.sonicar.tech/docs/planning/system-design).
* **Wet fuel deposits far more.** Fuel above 20 % moisture will foul a chimney in weeks.

## Checking draft [#checking-draft]

**Hold a strip of paper at the ash pit with the boiler running — it should deviate towards the ash pit.** That shows air is being drawn through the boiler.

Also confirm that the ventilation openings for inflow and exhaust air have not been restricted or blocked.

<Callout title="Chimney fan for comfort">
  For best comfort and minimal fume migration into the house, use a chimney fan when starting the
  boiler. Smoke hoods are a second option.
</Callout>

<NextStep href="/docs/planning/system-design" title="System design">
  Closed system, expansion tank, relief valve and return-temperature protection.
</NextStep>


# Fuel and storage (/docs/planning/fuel-storage)



**The UNI 60 burns any solid fuel, but the moisture content of your wood determines what you actually get out of it.** Dry oak carries nearly three times the usable energy per volume of the same oak at 50 % moisture.

## Accepted fuels [#accepted-fuels]

**Boilers are universal and work with all solid fuel: wood, coal, peat, mulch and woodchips.**

<Callout type="error" title="Never burn">
  Waste, plastics or flammable liquids. The combustion of these releases poisonous gases. If there
  is any danger of explosion, fire, or the emanation of combustion gas or steam indoors — stop the
  boiler.
</Callout>

## Moisture is the whole game [#moisture-is-the-whole-game]

**Combustion heat of absolutely dry wood is practically independent of species — about 8,112 BTU/lb.** What differs between species is density, so the useful comparison is energy per volume, not per pound.

Wood humidity falls into three categories:

| Category      | Moisture content |
| ------------- | ---------------- |
| Room-dry wood | 7 % – 20 %       |
| Air-dry wood  | 20 % – 50 %      |
| Driftwood     | 50 % – 70 %      |

**Seasoning timeline:** the lowest moisture content in a standing tree is in early winter. Firewood laid for **one year** under a canopy contains 20–25 % moisture; after **two years**, 13–17 %.

## Density by species [#density-by-species]

Weight of one cubic metre of wood:

| Species | Weight         |
| ------- | -------------- |
| Oak     | 1,540 lb       |
| Birch   | 1,410 lb       |
| Maple   | 1,160–1,440 lb |
| Alder   | 925–1,410 lb   |
| Pine    | 1,010–1,360 lb |
| Spruce  | 990 lb         |

## Calorific value by species and moisture [#calorific-value-by-species-and-moisture]

**Volume calorific value of wood depending on type and moisture.** Figures are calorific output for 2.2 lb.

| Species | kcal/dm @ 12 % | kcal/dm @ 25 % | kcal/dm @ 50 % | kWh/m @ 12 % | kWh/m @ 25 % | kWh/m @ 50 % |
| ------- | -------------- | -------------- | -------------- | ------------ | ------------ | ------------ |
| Oak     | 3,240          | 2,527          | 1,110          | 3,758        | 2,932        | 1,287        |
| Larch   | 2,640          | 2,059          | 904            | 3,062        | 2,389        | 1,049        |
| Birch   | 2,600          | 2,028          | 891            | 3,016        | 2,352        | 1,033        |
| Cedar   | 2,280          | 1,778          | 781            | 2,645        | 2,063        | 906          |
| Pine    | 2,080          | 1,622          | 712            | 2,413        | 1,882        | 826          |
| Aspen   | 1,880          | 1,466          | 644            | 2,181        | 1,701        | 747          |
| Spruce  | 1,800          | 1,404          | 617            | 2,088        | 1,629        | 715          |
| Fir     | 1,640          | 1,279          | 562            | 1,902        | 1,484        | 652          |
| Poplar  | 1,600          | 1,248          | 548            | 1,856        | 1,448        | 636          |

For comparison, **average coal** calorific heat output is 6,500 kcal, or 25.79 kBTU.

<Callout title="Read the table as a purchasing decision">
  A cord of oak at 12 % moisture delivers roughly &#x2A;*2.9×** the heat of the same cord at 50 %. Buying
  green wood and burning it the same winter is the most expensive fuel decision you can make.
</Callout>

## Storage [#storage]

<Steps>
  <Step>
    ### Keep it 4 ft from the boiler [#keep-it-4-ft-from-the-boiler]

    Do not stack the fuel near the boiler at a distance of less than **4 ft**.
  </Step>

  <Step>
    ### Split and stack under cover [#split-and-stack-under-cover]

    Stack under a canopy with airflow through the pile. Covered but ventilated beats sealed under a tarp, which traps moisture.
  </Step>

  <Step>
    ### Work two years ahead [#work-two-years-ahead]

    Cut and split this year for the winter after next. That is the difference between 20–25 % and 13–17 % moisture.
  </Step>

  <Step>
    ### Size for the firebox [#size-for-the-firebox]

    The UNI 60 takes logs up to **26 in** long and holds **58 gal** of volume. Cut to length before stacking; re-cutting in the boiler room is a job nobody enjoys.
  </Step>
</Steps>

## How much will you burn? [#how-much-will-you-burn]

**Estimate from the boiler's rated output and your building's heat demand, not from the firebox.** The UNI 60 runs 85–205 KBTU, and a full load can sustain up to 24 hours of operation. In practice, consumption depends on:

* the building's heat loss and how cold the season is;
* fuel species and moisture (see the tables above);
* whether the system has a buffer tank, which lets the boiler run at full, efficient output;
* and whether the boiler also makes domestic hot water year-round.

<NextStep href="/docs/installation/positioning" title="Positioning the boiler">
  Planning is done. Time to move 1,224 lb of steel into the room.
</NextStep>


# Hydronic system design (/docs/planning/system-design)



**Design the UNI 60 into a closed system with an expansion tank, a safety relief valve, return-temperature protection and thermal storage.** The boiler will physically run without most of those; it will not last without them.

<Callout type="error" title="Closed systems only, in practice">
  If the boiler is used on an **open** heating system the corrosion rate will be very fast and the
  warranty is avoided. The warranty period reflects that: **3 years** on the boiler body for open
  systems versus **10 years** for closed systems.
</Callout>

## The recommended scheme [#the-recommended-scheme]

<Figure src="/img/boiler/install-scheme.png" alt="MBtek recommended UNI boiler installation scheme showing the boiler, boiler station, buffer tank, flow bypass, expansion tank, PEX manifold with actuators and a radiant floor loop" caption="<><b>Recommended boiler installation scheme.</b> Boiler → boiler station → buffer tank → flow bypass → PEX manifold → emitters, with an expansion tank on the return side.</>" source="UNI Boiler Manual §8.1" width="1500" height="1622" />

**Material list for this scheme:**

| Item                           | Qty |
| ------------------------------ | --- |
| UNI boiler                     | 1   |
| Boiler station                 | 1   |
| Pump                           | 1   |
| Apollo PEX manifold            | 1   |
| Actuators                      | n   |
| Wi-Fi radiant thermostat       | n   |
| BF650 buffer tank              | 1   |
| DHW250 domestic hot water tank | 1   |
| 3-way motorised valve          | 1   |

<small>
  *n = number of zones required to heat.*
</small>

The PEX manifold connects your heating and cooling system using a fan coil unit, radiant floor, or the less efficient radiator and baseboard options.

## Mandatory components [#mandatory-components]

<Steps>
  <Step>
    ### Safety relief valve [#safety-relief-valve]

    **Never use the appliance without a relief valve.** Position the discharge drainage so that it is safe if the valve opens — it will discharge boiling water.
  </Step>

  <Step>
    ### Expansion tank [#expansion-tank]

    On closed **and** open heating systems, boilers must be installed with an open or membrane expansion tank. The volume depends on the heating volume and is calculated in the design of the heating system.
  </Step>

  <Step>
    ### Return-temperature protection [#return-temperature-protection]

    To avoid condensation, a thermostatic valve should hold the return above roughly **130 °F**. Where direct circulation is used **without** a thermostatic valve and the return falls below **122 °F**, the supply must be set to at least **149 °F**.
  </Step>

  <Step>
    ### Check valve on automatic make-up [#check-valve-on-automatic-make-up]

    If using automatic make-up water to the boiler, install a check valve according to local regulations. The system should be filled at a pressure not exceeding the maximum working boiler pressure.
  </Step>

  <Step>
    ### Thermal storage [#thermal-storage]

    A full burn produces more heat than most buildings need at that moment. A buffer tank captures it, cuts cycling and improves comfort — see [Buffer tank and hot water](./buffer-and-hot-water.mdx).
  </Step>
</Steps>

## Pressure and temperature envelope [#pressure-and-temperature-envelope]

| Parameter                         | Limit          |
| --------------------------------- | -------------- |
| Maximum operating pressure        | 15 psi         |
| Never exceed                      | 36 psi         |
| Maximum test pressure             | 50 psi         |
| Maximum water temperature         | 185 °F / 85 °C |
| Recommended boiler setpoint       | 149 °F / 65 °C |
| Minimum return temperature target | \~130 °F       |

## Natural circulation [#natural-circulation]

**If the system relies on natural circulation, install the boiler so the return water pipe sits below the radiator.** Gravity systems need that height difference to move water at all.

## Overheat behaviour [#overheat-behaviour]

**Design the system so heat has somewhere to go when the controller decides it must dump it.** Two controller behaviours force circulation:

* **Boiler cooling temperature** (MBtek recommends 78 °C / 172 °F): above this, *all* circulation pumps in the heating system start.
* **Maximum boiler temperature** (recommend 80 °C / 176 °F): external controls such as the room thermostat are ignored, and fan control functions are disabled.

If every zone can be closed off by actuators at once, the pumps will have nowhere to push water. Fit a **flow bypass** — it is in the recommended scheme for exactly this reason.

## Air and pressure in service [#air-and-pressure-in-service]

* Throughout the heating season, monitor the pressure in the system.
* Air must be removed during the first weeks of operation. Expect to vent repeatedly as dissolved air comes out of solution.

<NextStep href="/docs/planning/buffer-and-hot-water" title="Buffer tank and hot water">
  Sizing thermal storage, and how the controller makes domestic hot water.
</NextStep>


# Daily operation (/docs/operation/daily-operation)



**Day-to-day, a UNI 60 needs one load of fuel, one ash removal and one glance at the pressure gauge.** Everything else is weekly or seasonal — see the [maintenance schedule](https://uni.sonicar.tech/docs/maintenance/schedule).

## The daily routine [#the-daily-routine]

<Steps>
  <Step>
    ### Remove the ash [#remove-the-ash]

    **Every day, remove the ash from the boiler.** The ash pan sits outside the unit at the front of the ash door.

    Ash left in place blocks the grate and starves the fire of primary air.
  </Step>

  <Step>
    ### Check the external state of the boiler [#check-the-external-state-of-the-boiler]

    Check the boiler body, the controller, the sensors and the wiring, and clean them of dust.
  </Step>

  <Step>
    ### Load the firebox [#load-the-firebox]

    Turn the fan **off** first. Open the loading door slowly and stand to the side. Fill, then close the door tightly and restart the fan.
  </Step>

  <Step>
    ### Check system pressure [#check-system-pressure]

    Throughout the heating season, monitor pressure in the system. Working pressure must not exceed **15 psi**.
  </Step>

  <Step>
    ### Glance at the controller [#glance-at-the-controller]

    Boiler temperature at or near setpoint, no alarm LED, pumps running as expected.
  </Step>
</Steps>

## What the indicators are telling you [#what-the-indicators-are-telling-you]

| Indicator             | Normal                        | Investigate if                                                     |
| --------------------- | ----------------------------- | ------------------------------------------------------------------ |
| **START** flashing    | Ignition in progress          | It stays flashing for a long time — check fuel and draft           |
| **START** constant    | Automatic operation           | —                                                                  |
| **STOP** yellow       | Controller stopped            | It appears unexpectedly — likely quenching or shutdown temperature |
| **Fan**               | On during operation and purge | Off while the boiler is below setpoint                             |
| **CH pump**           | On above 35 °C / 95 °F        | Off with a hot boiler — check the pump and the relay               |
| **Alarm** pulsing red | —                             | Always. Open the list with `F`                                     |

## Good habits [#good-habits]

**These are the habits that separate a boiler holding 86 % efficiency from one drifting down into the seventies.**

* **Burn dry wood.** 20 % moisture or below. Wet wood roughly halves the usable energy and tars the chimney.
* **Load fully, then let it burn.** A gasification boiler is at its best running hot into storage, not smouldering at low air.
* **Do not open doors unnecessarily.** Every opening dumps heat and disturbs the combustion the controller is managing.
* **Keep the ash out.** Daily.
* **Keep the heat exchanger clean.** Weekly in mid-winter — soot and ash on the walls reduce heat transfer and efficiency.
* **Let the buffer tank do its job.** If the boiler is constantly in supervision, the system is undersized on storage, not oversized on boiler.

## When something is wrong [#when-something-is-wrong]

**Shut down the boiler in case of a problem**, and disconnect it from the mains before any repair, maintenance or cleaning.

If there is a fault in the electrical system — a short to the boiler body, deteriorating wire insulation — **immediately disconnect the boiler from the power supply and call after-sales service for repair**.

For a risk of explosion, ignition, gas contamination or fumes, follow the [emergency procedure](https://uni.sonicar.tech/docs/start/safety#emergency-procedure).

<NextStep href="/docs/operation/fuel" title="Fuel properties">
  Which wood gives you the most heat, and how dry it has to be.
</NextStep>


# First firing (/docs/operation/first-firing)



**The first firings must be carried out by a trained installer or service technician, and the boiler must not be left unsupervised during them.** By this point the system should be filled, vented, wired and configured — see the [commissioning checklist](https://uni.sonicar.tech/docs/installation/commissioning).

## Lighting the boiler [#lighting-the-boiler]

<Steps>
  <Step>
    ### Check the draft in the chimney [#check-the-draft-in-the-chimney]

    Hold a strip of paper at the ash pit — it should deviate to the side of the ash pit. Confirm the ventilation openings for inflow and exhaust have not been restricted or blocked.
  </Step>

  <Step>
    ### Set up the controller [#set-up-the-controller]

    Load the [MBtek recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings). Confirm the fan type is **WPA 07 / DM85** and the mode is **Brager Expert exhaust gases** (or **Brager Expert** without the PT1000 sensor).
  </Step>

  <Step>
    ### Fill the furnace with fuel [#fill-the-furnace-with-fuel]

    Use dry wood — aim for 20 % moisture or below. Logs up to **26 in**; the firebox holds **58 gal**.
  </Step>

  <Step>
    ### Ignite from the top or the bottom [#ignite-from-the-top-or-the-bottom]

    Both are acceptable. Top-down ignition generally produces less smoke on a cold start.

    <Callout type="error" title="Never use flammable liquids to start the fire">
      Use kindling and a firelighter.
    </Callout>
  </Step>

  <Step>
    ### Wait for the fuel to inflame [#wait-for-the-fuel-to-inflame]

    Monitor the combustion process **constantly** during this stage. Then close the door tightly.
  </Step>

  <Step>
    ### Activate "Start Fire" [#activate-start-fire]

    Run the **Start Fire** function in the controller. The **START** indicator flashes during ignition and becomes constant once the controller is in automatic operation mode.
  </Step>

  <Step>
    ### Watch the first cycle through [#watch-the-first-cycle-through]

    Stay with the boiler. Confirm:

    * the fan runs and the fan indicator lights;
    * the boiler temperature climbs;
    * at 35 °C / 95 °F the pumps start and the CH pump indicator lights;
    * the exhaust temperature settles into the 160–240 °C band (with the PT1000 fitted);
    * at setpoint the boiler drops into supervision and the fan starts pulsing.
  </Step>
</Steps>

## Adding fuel [#adding-fuel]

**Turn the fan OFF before adding more fuel, then observe the precautions.**

<Callout type="warn" title="Backdraught risk">
  Combustion running with a limited air supply can ignite suddenly when the door is opened and air
  rushes in. Open the door slowly and stand to the side. Do not open the doors for a long time while
  the boiler is firing.
</Callout>

Filling of fuel — wood, coal, briquettes — must be done **before** combustion, not into a roaring fire.

## If the fire fails to establish [#if-the-fire-fails-to-establish]

| Symptom                    | Likely cause                                                                                   |
| -------------------------- | ---------------------------------------------------------------------------------------------- |
| **Failed fireup** alarm    | Firing-up time expired without the boiler temperature rising above shutdown temperature + 2 °C |
| Fan hums but does not turn | Minimum fan speed too low — raise to 40 %                                                      |
| Smoke back into the room   | Poor draft: cold chimney, blocked flue, restricted ventilation openings, too many bends        |
| Fire dies after ignition   | Wet fuel, insufficient kindling, supervision settings too lean                                 |

Use a chimney fan on start-up for best comfort and minimal fume migration into the house. Smoke hoods are a second option.

## Optimising after the first burns [#optimising-after-the-first-burns]

<Callout title="Settings are a starting point">
  The boiler manual is explicit: to achieve high-quality and reliable operation, controller
  parameters must be optimised, and it is necessary to agree them with a professional instructed by
  your local distributor.
</Callout>

Watch the first few burns and adjust using the [tuning notes](https://uni.sonicar.tech/docs/controller/recommended-settings#tuning-notes).

## Flame bumper (older units) [#flame-bumper-older-units]

<Figure src="/img/install/flame-bumper-1.jpg" alt="Installer sliding the flame bumper deflector plate into the boiler through the open upper door" caption="<><b>Fitting the flame bumper.</b> The plate slides in above the loading chamber.</>" source="UNI Install Guide, page 3" width="414" height="286" max="430" />

<Figure src="/img/install/flame-bumper-2.jpg" alt="Flame bumper deflector plate seated in position inside the boiler, seen through the open door" caption="<><b>Seated in position.</b> It stops the heat of the flame reaching the upper door — mandatory on older units, because the door will burn without it.</>" source="UNI Install Guide, page 3" width="505" height="280" max="460" />

If you are commissioning an older UNI unit, confirm the flame bumper is fitted before firing.

<NextStep href="/docs/operation/daily-operation" title="Daily operation">
  Loading, ash removal and running the boiler through the week.
</NextStep>


# Fuel properties (/docs/operation/fuel)



**Combustion heat of absolutely dry wood is about 8,112 BTU/lb regardless of species — so what separates oak from spruce is density, and what separates good wood from bad is moisture.**

## Accepted fuels [#accepted-fuels]

**UNI boilers are universal and work with all solid fuel:** wood, coal, peat, mulch and woodchips.

<Callout type="error" title="Never burn waste">
  The combustion of waste, plastics or flammable liquids can release poisonous gases. Use only
  recommended fuels. If there is danger of explosion, fire, or the emanation of combustion gas
  indoors or steam — stop the boiler.
</Callout>

## Moisture categories [#moisture-categories]

| Category      | Moisture content |
| ------------- | ---------------- |
| Room-dry wood | 7 % – 20 %       |
| Air-dry wood  | 20 % – 50 %      |
| Driftwood     | 50 % – 70 %      |

**Higher moisture in wood, the lower its calorific value.** The lowest moisture content to cut a tree is in early winter. Firewood laid for a year under a canopy contains &#x2A;*20–25 %** moisture; after two years, &#x2A;*13–17 %**.

## Density by species [#density-by-species]

Weight of one cubic metre:

| Species | Weight         |
| ------- | -------------- |
| Oak     | 1,540 lb       |
| Birch   | 1,410 lb       |
| Maple   | 1,160–1,440 lb |
| Alder   | 925–1,410 lb   |
| Pine    | 1,010–1,360 lb |
| Spruce  | 990 lb         |

## Volume calorific value [#volume-calorific-value]

**The volume calorific value of wood depending on type and moisture.** Calorific output for 2.2 lb.

| Species | kcal/dm 12 % | kcal/dm 25 % | kcal/dm 50 % | kWh/m 12 % | kWh/m 25 % | kWh/m 50 % |
| ------- | ------------ | ------------ | ------------ | ---------- | ---------- | ---------- |
| **Oak** | **3,240**    | 2,527        | 1,110        | 3,758      | 2,932      | 1,287      |
| Larch   | 2,640        | 2,059        | 904          | 3,062      | 2,389      | 1,049      |
| Birch   | 2,600        | 2,028        | 891          | 3,016      | 2,352      | 1,033      |
| Cedar   | 2,280        | 1,778        | 781          | 2,645      | 2,063      | 906        |
| Pine    | 2,080        | 1,622        | 712          | 2,413      | 1,882      | 826        |
| Aspen   | 1,880        | 1,466        | 644          | 2,181      | 1,701      | 747        |
| Spruce  | 1,800        | 1,404        | 617          | 2,088      | 1,629      | 715        |
| Fir     | 1,640        | 1,279        | 562          | 1,902      | 1,484      | 652        |
| Poplar  | 1,600        | 1,248        | 548          | 1,856      | 1,448      | 636        |

**Average coal** calorific heat output is 6,500 kcal, or **25.79 kBTU**.

<Callout title="The two decisions that matter most">
  1. **Species** — oak carries roughly 2× the energy per volume of poplar at the same moisture.
  2. **Moisture** — the same oak loses roughly 66 % of its value going from 12 % to 50 % moisture.

  Get both right and the same firebox delivers several times the heat.
</Callout>

## Fuel and maintenance intervals [#fuel-and-maintenance-intervals]

**Deposits and gum formation by condensation depend on the fuel type — wood more than coal — on the chimney draft, and on the operation mode.**

| Fuel              | Chimney fouling | Notes                                          |
| ----------------- | --------------- | ---------------------------------------------- |
| Dry hardwood      | Moderate        | Best balance of output and cleanliness         |
| Wet wood          | Severe          | Tar and condensation; expect frequent sweeping |
| Coal              | Lower than wood | Higher calorific density, more ash volume      |
| Woodchips / mulch | Variable        | Depends heavily on moisture                    |

MBtek recommends **boiler cleaning in mid-winter at least once a week** — see [Cleaning](https://uni.sonicar.tech/docs/maintenance/cleaning).

## Sizing your fuel [#sizing-your-fuel]

| Property                 | UNI 60                       |
| ------------------------ | ---------------------------- |
| Maximum log length       | 26 in                        |
| Firebox volume           | 58 gal                       |
| Burn time on a full load | Up to 24 hours               |
| Fuel storage clearance   | 4 ft minimum from the boiler |

<NextStep href="/docs/operation/seasonal" title="Seasonal shutdown">
  Ending the heating season without leaving problems for next year.
</NextStep>


# Seasonal shutdown and start-up (/docs/operation/seasonal)



**Close the season with a deep clean and leave the system full — then run the pre-season checks before the first fire in autumn.** A boiler left dirty over summer corrodes; a boiler left empty or exposed to frost fails differently but just as expensively.

## End of season [#end-of-season]

<Steps>
  <Step>
    ### Burn out and cool down [#burn-out-and-cool-down]

    Let the last load burn out. Wait until the boiler has cooled fully before opening it up.
  </Step>

  <Step>
    ### Disconnect from the mains [#disconnect-from-the-mains]

    Shut down the boiler from the mains before any cleaning or maintenance work.
  </Step>

  <Step>
    ### Clean thoroughly [#clean-thoroughly]

    At the time of a warranty repair the equipment must be cleaned of soot, tar and other contaminants — so do it now, while the season is fresh in memory:

    * remove all ash;
    * scrape the surfaces of the furnace and the loading chamber;
    * clean the air ducts in the combustion chamber with a suitable tool;
    * brush the top of the heat exchanger clear of soot.

    See [Cleaning](https://uni.sonicar.tech/docs/maintenance/cleaning).
  </Step>

  <Step>
    ### Sweep the chimney [#sweep-the-chimney]

    Soot and condensation left over summer deteriorate joints. See [Chimney care](https://uni.sonicar.tech/docs/maintenance/chimney-care).
  </Step>

  <Step>
    ### Leave the system full and pressurised [#leave-the-system-full-and-pressurised]

    Do **not** drain the system. An empty steel boiler rusts internally.
  </Step>

  <Step>
    ### Protect against frost [#protect-against-frost]

    **Do not leave the boiler with water at an ambient temperature below +41 °F / +5 °C.** If the boiler room can drop below that over summer or in an unheated period, address it before you walk away.
  </Step>

  <Step>
    ### Consider Summer mode [#consider-summer-mode]

    If the boiler also makes domestic hot water and you intend to keep using it through summer, switch the HUW module to **Summer mode** — see [Hot water](https://uni.sonicar.tech/docs/controller/hot-water).
  </Step>
</Steps>

## Before the heating season [#before-the-heating-season]

**Before the heating season and during its period, it is necessary to check the technical condition of the wires, check the fastening of the regulator, and clean it from dust and other contaminants.**

<Accordions>
  <Accordion title="Electrical check">
    Wire condition, regulator fastening, dust removal. Look for any sign of a short to the boiler body or deteriorating insulation — if found, disconnect and call service.
  </Accordion>

  <Accordion title="Water and pressure">
    Check system pressure and top up if needed, using water within the 2 ppm hardness limit. Vent the high points.
  </Accordion>

  <Accordion title="Relief valve">
    Confirm the safety relief valve is free and its discharge is unobstructed.
  </Accordion>

  <Accordion title="Expansion tank">
    Check the charge pressure. A waterlogged tank shows up as pressure swinging with temperature.
  </Accordion>

  <Accordion title="Chimney and draft">
    Sweep if not already done. Verify draft with a paper strip at the ash pit, and confirm ventilation openings are clear.
  </Accordion>

  <Accordion title="Door gaskets">
    Inspect the sealing cord on each door. It is a consumable and not covered by warranty — replace it before it costs you efficiency.
  </Accordion>

  <Accordion title="Controller settings">
    Confirm the settings are still those recorded at commissioning, and note the software version.
  </Accordion>

  <Accordion title="Fuel stock">
    Check moisture. Wood cut this spring will not be ready this winter.
  </Accordion>
</Accordions>

<SupportCta title="Pre-season service" />

<NextStep href="/docs/maintenance/schedule" title="Maintenance schedule">
  What to do daily, weekly and seasonally, in one table.
</NextStep>


# Clearance reference (/docs/resources/clearance-reference)



**One page with the clearance table, both drawings and the service-space figures — print it and take it to site.**

<Callout type="warn" title="Verify against local code">
  Clearance requirements for wood stoves and stove pipes vary by region. Consult local regulations
  or a certified building inspector. Always verify based on pipe type — single-wall or double-wall —
  and installation location. Keep documentation of clearance distances and code compliance for
  insurance and reference purposes.
</Callout>

## Clearance for safety and service [#clearance-for-safety-and-service]

| Key   | Reference                    | Required distance | Notes                                           |
| ----- | ---------------------------- | ----------------- | ----------------------------------------------- |
| **A** | Back wall to boiler          | **24 in**         | Minimum incline of 3°                           |
| **B** | Side wall to boiler (right)  | **24 in**         | Minimum distance                                |
| **C** | Side wall to boiler (left)   | **24 in**         | Minimum distance                                |
| **D** | Front of boiler              | **36 in**         | Required distance for cleaning the boiler       |
| **E** | Ceiling to boiler            | **28 in**         | Minimum distance for cleaning the boiler        |
| **F** | Combustible to exhaust pipe  | **12 in**         | Minimum 6 in for double-wall stove exhaust pipe |
| **G** | Combustibles to boiler       | **12 in**         | Minimum distance                                |
| **H** | Distance to non-combustibles | **6 in**          | Minimum distance for non-combustibles           |

## Side elevation [#side-elevation]

<Figure src="/img/boiler/clearance-side.png" alt="Side elevation of the boiler against a masonry wall showing clearance E from the ceiling, F from the flue pipe to combustible material, G from the upper boiler body and H from the lower casing" caption="<><b>Side view</b> — E ceiling, F flue pipe to combustibles, G and H horizontal clearances.</>" source="UNI Boiler Manual, clearance addendum" width="1190" height="1144" />

## Plan view [#plan-view]

<Figure src="/img/boiler/clearance-plan.png" alt="Plan view of the boiler in a masonry room showing clearance A to the back wall, B and C to the side walls and D in front of the boiler" caption="<><b>Plan view</b> — A back wall, B and C side walls, D front working space.</>" source="UNI Boiler Manual, clearance addendum" width="918" height="946" />

## Service space [#service-space]

**Section 7.2 of the boiler manual adds separate working-space figures. Where they differ from the clearance table, build to the larger.**

| Reference                                      | Distance       |
| ---------------------------------------------- | -------------- |
| Frontage                                       | Minimum 4 ft   |
| Rear wall                                      | Minimum 2 in   |
| One side, for access to the rear of the boiler | At least 16 in |

**In practice: 4 ft in front and 24 in all round** satisfies both sets of figures.

## Fuel storage [#fuel-storage]

**Do not stack the fuel near the boiler at a distance of less than 4 ft.**

## Boiler footprint [#boiler-footprint]

| Dimension | UNI 60   |
| --------- | -------- |
| Width     | 30 in    |
| Depth     | 36 in    |
| Height    | 65 in    |
| Weight    | 1,224 lb |
| Tolerance | ±5 %     |

**Total room footprint** including the minimum clearances: roughly **78 in wide** (30 + 24 + 24) by **96 in deep** (36 + 24 back + 36 front), with **93 in** of height (65 + 28).

## Material fire safety ratings [#material-fire-safety-ratings]

| Class   | Flame spread index | Fire resistance |
| ------- | ------------------ | --------------- |
| Class A | 0–25               | Highest         |
| Class B | 26–75              | Moderate        |
| Class C | 76–200             | Lowest          |

The boiler's own materials:

| Material                | Thickness | Class rating |
| ----------------------- | --------- | ------------ |
| Mineral wool insulation | 1½ in     | Class A1     |
| EN 10051/10 mild steel  | ¼ in      | Class A\*    |

<small>
  \* Subject to individual material tests. Ratings are determined by standardised tests such as ASTM E84 and E119.
</small>

<NextStep href="/docs/resources/glossary" title="Glossary">
  The terms used across this documentation, defined.
</NextStep>


# Downloads (/docs/resources/downloads)



**Every page on this site is written from the five documents below — download them if you want the originals on site, offline, or in the installer's hands.**

<Cards>
  <Card title="UNI Boiler Manual (PDF)" href="/downloads/uni-boiler-manual.pdf" description="16 pages. Overview, technical data, delivery contents, safety, chimney requirements, boiler structure, installation, fuel storage, maintenance, fuel properties, warranty, clearances and fire safety ratings." />

  <Card title="UNI Install Guide (PDF)" href="/downloads/uni-install-guide.pdf" description="3 pages. MBtek recommended controller settings, sensor placement, 110 V pump wiring, room thermostat, flame bumper, blank screen diagnosis and DZT thermal protection sensors." />

  <Card title="TIS Tronic 260U Controller Manual (PDF)" href="/downloads/tis-tronic-260u-controller-manual.pdf" description="29 pages. Safety, general information, control panel, first launch, operating modes, HUW module, room thermostat, quenching, every parameter, alarms, board diagram, sensors and fuse." />

  <Card title="TIS Tronic 260U Replacement Guide (PDF)" href="/downloads/tis-tronic-260u-replacement-guide.pdf" description="2 pages. Five-step procedure for fitting a TIS Tronic 260U in place of an older TIS Tronic 83 on TIS UNI and TIS HARD PLUS 150 boilers." />

  <Card title="MBtek Wood Boiler Specifications (PDF)" href="/downloads/mbtek-wood-boiler-specifications.pdf" description="The current comparison chart for the whole range: PRO 11 and 30, UNI 15, 40, 60, 95, 150, 300, 500 and 1000." />
</Cards>

## Which document covers what [#which-document-covers-what]

| Topic                               | Document                         | Covered here                                                                               |
| ----------------------------------- | -------------------------------- | ------------------------------------------------------------------------------------------ |
| Specifications and the model range  | Specification sheet              | [Specifications](https://uni.sonicar.tech/docs/start/specifications)                                               |
| Boiler structure and components     | Boiler manual §6                 | [How it works](https://uni.sonicar.tech/docs/start/how-it-works)                                                   |
| Safety, pressures and temperatures  | Boiler manual §4, §9             | [Safety](https://uni.sonicar.tech/docs/start/safety)                                                               |
| Chimney                             | Boiler manual §5                 | [Chimney requirements](https://uni.sonicar.tech/docs/planning/chimney)                                             |
| Hydronic installation               | Boiler manual §7, §8             | [System design](https://uni.sonicar.tech/docs/planning/system-design)                                              |
| Water quality                       | Boiler manual §7.1               | [Filling](https://uni.sonicar.tech/docs/installation/filling)                                                      |
| Clearances                          | Boiler manual clearance addendum | [Boiler room](https://uni.sonicar.tech/docs/planning/boiler-room)                                                  |
| Fuel properties                     | Boiler manual §10                | [Fuel](https://uni.sonicar.tech/docs/operation/fuel)                                                               |
| Warranty                            | Boiler manual §12                | [Warranty](https://uni.sonicar.tech/docs/support/warranty)                                                         |
| Recommended controller settings     | Install guide p1                 | [Recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings)                              |
| Sensor placement and pump wiring    | Install guide p2                 | [Electrical](https://uni.sonicar.tech/docs/installation/electrical), [Pump wiring](https://uni.sonicar.tech/docs/installation/pump-wiring) |
| Troubleshooting quick fixes         | Install guide p3                 | [Common problems](https://uni.sonicar.tech/docs/troubleshooting/common-problems)                                   |
| Controller operation and parameters | Controller manual                | [TIS Tronic 260U](https://uni.sonicar.tech/docs/controller/overview)                                               |
| Controller retrofit                 | Replacement guide                | [Mounting the controller](https://uni.sonicar.tech/docs/installation/controller-mounting)                          |

## Machine-readable versions [#machine-readable-versions]

**This documentation is also published in formats built for AI answer engines and scripts.**

| Format               | URL                                           |
| -------------------- | --------------------------------------------- |
| Site index for LLMs  | [/llms.txt](https://uni.sonicar.tech/llms.txt)                        |
| Full text for LLMs   | [/llms-full.txt](https://uni.sonicar.tech/llms-full.txt)              |
| Markdown of any page | append `/content.md` under `/llms.mdx/docs/…` |
| Sitemap              | [/sitemap.xml](https://uni.sonicar.tech/sitemap.xml)                  |

Each documentation page also has a **Copy Markdown** button in its header.

<NextStep href="/docs/resources/parameter-reference" title="Parameter reference">
  Every controller parameter with its range, default and MBtek value.
</NextStep>


# Glossary (/docs/resources/glossary)



**The terms used in this documentation, in plain language.** Several come from the original European manuals and are not the words a North American installer would reach for first.

<Accordions>
  <Accordion title="Brager Expert">
    An adaptive combustion algorithm in the TIS Tronic 260U. It automatically selects fan parameters to match the boiler's output to the building's actual heat demand, while aiming for the set boiler temperature. See [Operating modes](https://uni.sonicar.tech/docs/controller/operating-modes).
  </Accordion>

  <Accordion title="Brager Expert exhaust gases">
    The variant of the Brager Expert algorithm that targets a constant **exhaust gas temperature** rather than a water temperature. Requires a PT1000 sensor on `T3`. MBtek's recommended mode for the UNI 60.
  </Accordion>

  <Accordion title="Buffer tank">
    Thermal storage between the boiler and the heating distribution. It captures the heat of a full burn that the building cannot use at that moment, reducing cycling and improving comfort. See [Buffer tank and hot water](https://uni.sonicar.tech/docs/planning/buffer-and-hot-water).
  </Accordion>

  <Accordion title="CH">
    Central heating. The controller uses it for the space-heating circuit — `Q3` is the CH pump output, and the CH sensor is the boiler water sensor on `T1`.
  </Accordion>

  <Accordion title="DHW">
    Domestic hot water. The controller labels this **HUW**.
  </Accordion>

  <Accordion title="DZT-1 / DZT-2">
    Thermal protection sensors that connect to `I1`. DZT-1 opens at 185 °F / 85 °C and closes at 140 °F / 60 °C; DZT-2 opens at 200 °F / 95 °C and closes at 155 °F / 70 °C.
  </Accordion>

  <Accordion title="Fan deceleration (slowdown) threshold">
    How many degrees before the set temperature the fan begins slowing down. Range 3–30 °C; MBtek value 12 °C / 21 °F.
  </Accordion>

  <Accordion title="Firing-up time">
    The maximum time the fire-up stage may last. Ignition counts as successful if the boiler temperature rises above the shutdown temperature + 2 °C within that time. Range 30–120 min.
  </Accordion>

  <Accordion title="Gasification">
    Burning wood in two stages: the fuel is heated to release combustible gas, and that gas is then burned in a second, hotter stage. It extracts more energy from the same wood than a simple stove.
  </Accordion>

  <Accordion title="HUW">
    The controller's term for domestic hot water. `Q4` is the HUW pump output; `T2` is the tank sensor.
  </Accordion>

  <Accordion title="Hysteresis">
    The gap between switching off and switching back on. With a 60 °C setpoint and 2 °C boiler hysteresis, the boiler returns from supervision to operation at 58 °C. Range 1–3 °C.
  </Accordion>

  <Accordion title="KTY-81-210">
    The sensor type used for the boiler (`T1`) and hot water (`T2`) temperature sensors.
  </Accordion>

  <Accordion title="Operation (mode stage)">
    The stage in which the boiler is actively driving toward setpoint, with the fan running under the maximum, minimum and deceleration settings.
  </Accordion>

  <Accordion title="PT1000">
    The exhaust gas temperature sensor type, fitted to `T3`. Not included in the standard controller kit.
  </Accordion>

  <Accordion title="Purge time">
    How many seconds the fan runs during each supervision pulse. Range 5–60 s; MBtek value 10 s. Also called fan ON time.
  </Accordion>

  <Accordion title="Quenching / extinguishing">
    The controller's term for shutting down because the fire has gone out. Triggered by boiler temperature or exhaust gas temperature. See [Quenching](https://uni.sonicar.tech/docs/controller/quenching).
  </Accordion>

  <Accordion title="STB">
    The independent bimetallic safety thermostat on `I1`. It cuts the fan above roughly 90 °C water. Per PN-EN 303-5:2012 the fan cannot restart until the water is below 60 °C and the alarm is manually reset.
  </Accordion>

  <Accordion title="Supervision">
    The stage after the boiler reaches setpoint. The fan stops driving and only pulses briefly at low speed to keep the coals alive. See [User menu](https://uni.sonicar.tech/docs/controller/user-menu#how-supervision-works).
  </Accordion>

  <Accordion title="Three-pass">
    The flue gas path in the UNI: gas leaves the furnace and turns through successive passes, giving up heat to the water jacket, before reaching the chimney connection.
  </Accordion>

  <Accordion title="TIS Tronic 260U">
    The current electronic regulator fitted to UNI boilers, made by BelKomin LLC. Replaces the older TIS Tronic 83.
  </Accordion>

  <Accordion title="WPA 07 / DM85">
    The fan type to select in the controller for UNI units. Selecting the wrong type creates a dead band in which changing fan parameters has no visible effect.
  </Accordion>
</Accordions>

<NextStep href="/docs/support/faq" title="FAQ">
  The questions owners and installers ask most often.
</NextStep>


# Parameter reference (/docs/resources/parameter-reference)



**Every parameter the TIS Tronic 260U exposes, with its range, factory default and MBtek's value for the UNI 60.** Where the MBtek column is blank, the factory default stands.

## User menu [#user-menu]

| Parameter                      | Range           | Factory default | MBtek UNI 60 |
| ------------------------------ | --------------- | --------------- | ------------ |
| Fan maximum capacity           | min + 1 … 100 % | 50 %            | **80 %**     |
| Fan minimum capacity           | 1 % … max − 1 % | 10 %            | **40 %**     |
| Fan capacity in supervision    | 1 … 100 %       | 25 %            | **35 %**     |
| Purge time (fan ON)            | 5 … 60 s        | 10 s            | **10 s**     |
| Time between blowups (fan OFF) | 1 … 20 min      | 5 min           | **5 min**    |

## Thermostat menu [#thermostat-menu]

| Parameter              | Range       | Factory default | MBtek UNI 60     |
| ---------------------- | ----------- | --------------- | ---------------- |
| CH room thermostat     | On / off    | —               | Per installation |
| CH pump operating time | 30 … 250 s  | 30 s            | —                |
| CH pump pause time     | 0 … 240 min | 1 min           | —                |

## HUW menu [#huw-menu]

| Parameter                | Range                 | Factory default | MBtek UNI 60     |
| ------------------------ | --------------------- | --------------- | ---------------- |
| HUW operating mode       | Off / Summer / Winter | Off             | Per installation |
| HUW priority             | On / off              | —               | Per installation |
| HUW temperature increase | 5 … 15 °C             | 5 °C            | —                |
| HUW operating time       | 10 … 240 min          | 30 min          | —                |
| HUW hysteresis           | 1 … 15 °C             | 5 °C            | —                |

## Boiler settings [#boiler-settings]

| Parameter                                                  | Range                                                  | Factory default | MBtek UNI 60                    |
| ---------------------------------------------------------- | ------------------------------------------------------ | --------------- | ------------------------------- |
| Boiler operating mode                                      | Standard / Brager Expert / Brager Expert exhaust gases | Standard        | **Brager Expert exhaust gases** |
| Brager Expert exhaust gases firing-up time                 | 0 … 250 min                                            | 10 min          | **10 min**                      |
| Fan slowdown threshold                                     | 3 … 30 °C                                              | 12 °C           | **12 °C / 21 °F**               |
| Boiler hysteresis                                          | 1 … 3 °C                                               | 2 °C            | **2 °C / 5 °F**                 |
| Maximum boiler temperature                                 | 70 … 90 °C                                             | 85 °C           | **80 °C / 176 °F**              |
| Boiler shutdown temperature                                | 30 … 45 °C                                             | 35 °C           | **35 °C / 95 °F**               |
| Pump start temperature                                     | 35 … 60 °C                                             | 35 °C           | **35 °C / 95 °F**               |
| Fan type                                                   | 07 / DM85 · 06/145 / DM80                              | —               | **WPA 07 / DM85**               |
| Firing-up time                                             | 30 … 120 min                                           | 120 min         | **120 min**                     |
| Boiler cooling temperature                                 | 70 … 85 °C                                             | 78 °C           | **78 °C / 172 °F**              |
| Exhaust gases temperature sensor                           | On / off                                               | Off             | **On** (PT1000 required)        |
| Fuel shortage detection method                             | Boiler sensor / exhaust sensor                         | Boiler sensor   | Per installation                |
| Exhaust gas temperature, fuel shortage detection threshold | 30–90 °C                                               | —               | Per installation                |
| Fuel shortage detection time                               | 2–200 min                                              | —               | Per installation                |
| Fuel shortage CH pump OFF                                  | YES / NO                                               | —               | Per installation                |
| CH pump shutdown delay                                     | 5–120 min                                              | —               | Per installation                |

## Main screen setpoints [#main-screen-setpoints]

| Setpoint                | Where                                                  | MBtek UNI 60                |
| ----------------------- | ------------------------------------------------------ | --------------------------- |
| Boiler temperature      | Boiler main screen, `UP` / `DOWN`                      | **65 °C / 149 °F**          |
| Exhaust gas temperature | Exhaust main screen (Brager Expert exhaust gases only) | **160–240 °C / 320–464 °F** |
| HUW temperature         | HUW main screen, `UP` / `DOWN`                         | Per installation            |

## Informational items [#informational-items]

| Item                      | Purpose                                          |
| ------------------------- | ------------------------------------------------ |
| Brager Expert             | Advanced options for the Brager Expert algorithm |
| Software version          | The installed controller software version        |
| Reset to default settings | Return to factory defaults                       |
| Language selection        | Interface language                               |

## Device parameters [#device-parameters]

| Property                                | Value                    |
| --------------------------------------- | ------------------------ |
| Power                                   | 230 V / 50 Hz AC         |
| Relative humidity                       | 30 … 75 %                |
| Ambient temperature                     | 5 … 40 °C                |
| Fan output `Q1`                         | 1 A                      |
| Central pump output `Q3`                | 1 A                      |
| HUW pump output `Q4`                    | 1 A                      |
| Power consumption (no external devices) | 4.5 W                    |
| Fuse                                    | 250 V, 3.15 A, 5 × 20 mm |

<NextStep href="/docs/resources/clearance-reference" title="Clearance reference">
  The clearance table and drawings on one page.
</NextStep>


# Alarm codes (/docs/troubleshooting/alarm-codes)



**Alarms show on the main screen and pulse the red LED on the right of the front panel.** Press `F` to open the alarm list, `UP` / `DOWN` to scroll, `STOP` to delete.

## Full alarm list [#full-alarm-list]

| Alarm                                                    | Trigger                                                                                | Resolution                                                                                                                                                                    |
| -------------------------------------------------------- | -------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Boiler temperature measurement error**                 | `T1` sensor missing or damaged                                                         | Check the sensor in the immersion well and the wiring at `T1`. Test the KTY-81-210 against the [resistance table](https://uni.sonicar.tech/docs/controller/alarms#boiler-sensor-resistance-reference) |
| **HUW overheating**                                      | Hot water tank temperature exceeded **85 °C**                                          | Check the HUW pump on `Q4`, the `T2` sensor position, the HUW setpoint and the temperature-increase value                                                                     |
| **Temperature measurement error, HUW**                   | `T2` sensor missing or damaged                                                         | Check the wiring at `T2` and sensor continuity                                                                                                                                |
| **Exhaust gas temperature measurement error**            | `T3` sensor missing or damaged                                                         | Confirm the PT1000 is fitted and wired. Activating the sensor in the menu without fitting it produces this alarm                                                              |
| **Lack of fuel**                                         | The quenching condition was met — by boiler temperature or by exhaust temperature      | Reload. Then review fuel quality and the [fuel shortage thresholds](https://uni.sonicar.tech/docs/controller/quenching)                                                                               |
| **Failed fireup**                                        | The firing-up time expired without the boiler rising above shutdown temperature + 2 °C | Check draft, fuel moisture, fan operation and minimum fan speed                                                                                                               |
| **Exceeding the boiler emergency temperature threshold** | Boiler temperature exceeded **94 °C**; the device switches to boiler protection mode   | Check pumps, flow path, zone actuators, the bypass and the boiler cooling temperature setting                                                                                 |
| **Overheating STB**                                      | External safety thermostat tripped (\~90 °C water)                                     | Boiler temperature must fall below **60 °C**, then reset manually on the panel                                                                                                |

## Clearing an alarm [#clearing-an-alarm]

<Steps>
  <Step>
    Resolve the underlying cause. An alarm cleared without a fix returns immediately.
  </Step>

  <Step>
    Press `F` to open the alarm list.
  </Step>

  <Step>
    Scroll with `UP` / `DOWN`.
  </Step>

  <Step>
    Press `STOP` to delete the error.
  </Step>
</Steps>

<Callout type="warn" title="STB is different">
  An STB overheating alarm cannot be cleared until the boiler water temperature has fallen below
  **60 °C**. This is required by PN-EN 303-5:2012 and is deliberate — it stops the fan restarting
  into a boiler that is still dangerously hot.
</Callout>

## Alarms by urgency [#alarms-by-urgency]

| Urgency                      | Alarms                                                                                           |
| ---------------------------- | ------------------------------------------------------------------------------------------------ |
| **Stop and investigate now** | Exceeding the boiler emergency temperature threshold · Overheating STB · HUW overheating         |
| **Fix before the next burn** | Boiler temperature measurement error · Exhaust gas temperature measurement error · Failed fireup |
| **Routine**                  | Lack of fuel · Temperature measurement error HUW (if hot water is not in use)                    |

## The temperature ladder [#the-temperature-ladder]

**Knowing where each threshold sits makes most alarms self-explanatory:**

| Temperature    | What happens                                                                 |
| -------------- | ---------------------------------------------------------------------------- |
| 35 °C / 95 °F  | Pumps start (pump start temperature)                                         |
| 35 °C / 95 °F  | Below this, boiler goes to STOP (boiler shutdown temperature)                |
| 65 °C / 149 °F | Setpoint — boiler enters supervision                                         |
| 78 °C / 172 °F | All circulation pumps forced on (boiler cooling temperature)                 |
| 80 °C / 176 °F | External controls ignored, fan control disabled (maximum boiler temperature) |
| 85 °C          | HUW overheating alarm threshold                                              |
| \~90 °C        | STB cuts the fan (hardware)                                                  |
| 94 °C          | Emergency threshold alarm, boiler protection mode                            |

<NextStep href="/docs/resources/downloads" title="Downloads">
  The original PDF manuals this documentation was built from.
</NextStep>


# Common problems (/docs/troubleshooting/common-problems)



**Start with the symptom, not the component.** Every entry here links to the page with the full procedure.

## The fan does not turn, or turns very slowly [#the-fan-does-not-turn-or-turns-very-slowly]

**If your fan makes a humming sound and does not turn, the minimum fan speed is too low.**

<Steps>
  <Step>
    Go to **boiler settings** and set the &#x2A;*minimum fan speed to 40 %**.
  </Step>

  <Step>
    Set the &#x2A;*maximum fan speed to 80 %**.
  </Step>

  <Step>
    Confirm **fan type = WPA 07 / DM85**. The wrong fan type creates a dead band where parameter changes produce no visible effect.
  </Step>
</Steps>

→ [Recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings)

## Blank screen [#blank-screen]

**Verify the connection using the electrical diagram, and make sure the controller is switched ON.** Then verify these parameters with a multimeter:

<Steps>
  <Step>
    **220 V on `L` and `N`.**
  </Step>

  <Step>
    **Controller fuse continuity.** 250 V, 3.15 A, 5 × 20 mm.
  </Step>

  <Step>
    **Continuity at terminal `I1`.** If there is none, jump this contact to test — an open STB circuit will hold the controller down.
  </Step>

  <Step>
    **If none of this works**, disconnect everything from the controller except `L`, `N` and the jumpers, then retest.
  </Step>
</Steps>

Also check the `TR2_DISP` panel ribbon, especially after a controller swap.

→ [Wiring reference](https://uni.sonicar.tech/docs/controller/wiring-reference)

## STB overheating [#stb-overheating]

**The external safety thermostat has tripped — the water reached roughly 90 °C.**

<Figure src="/img/install/alarm-stb.jpg" alt="Controller alarm screen reading: Overheating of the boiler, STB is disabled" caption="<><b>The alarm as the controller shows it.</b></>" source="UNI Install Guide, page 3" width="849" height="255" max="420" />

To clear the alarm the boiler temperature must fall **below 60 °C**, and the alarm must be reset manually on the control panel. Per PN-EN 303-5:2012 the fan cannot restart on its own.

| Likely cause                        | Check                                                        |
| ----------------------------------- | ------------------------------------------------------------ |
| Pump not running                    | `Q3` output, pump power, 220 VAC relay for 120 V circulators |
| All zones closed, no bypass         | Fit a flow bypass                                            |
| Pump start temperature too high     | MBtek value 35 °C / 95 °F                                    |
| Boiler cooling temperature too high | MBtek value 78 °C / 172 °F                                   |
| Air lock                            | Vent the system                                              |
| Power outage mid-burn               | Expected — reload after power returns                        |

If you need to operate at a higher temperature, order a **DZT-2** (opens 200 °F / 95 °C) and connect to `I1`.

→ [Alarms](https://uni.sonicar.tech/docs/controller/alarms#stb-overheating-in-detail)

## Smoke comes into the room [#smoke-comes-into-the-room]

| Cause                          | Fix                                                                         |
| ------------------------------ | --------------------------------------------------------------------------- |
| Poor draft                     | Check with a paper strip at the ash pit — it should deviate towards the pit |
| Cold chimney                   | Insulate exposed runs; use a chimney fan on start-up                        |
| Blocked ventilation openings   | Clear the inflow and exhaust openings                                       |
| Soot-narrowed flue             | Sweep                                                                       |
| Too many bends                 | Re-route if possible                                                        |
| Door opened during a lean burn | Open slowly, stand to the side                                              |

→ [Chimney care](https://uni.sonicar.tech/docs/maintenance/chimney-care)

## The upper door is burning (older units) [#the-upper-door-is-burning-older-units]

**On older units a flame bumper is mandatory — the upper door will burn without it.** It is a deflector that stops the heat of the flame reaching the door.

<Figure src="/img/install/flame-bumper-2.jpg" alt="Flame bumper deflector plate seated inside the boiler above the loading chamber" caption="Flame bumper — mandatory on older units." source="UNI Install Guide, page 3" width="505" height="280" max="440" />

## Failed fire-up [#failed-fire-up]

**The firing-up time expired without the boiler temperature rising above shutdown temperature + 2 °C.**

| Check          | Detail                                             |
| -------------- | -------------------------------------------------- |
| Fuel moisture  | Aim for 20 % or below. Wet wood will not establish |
| Draft          | Paper-strip test at the ash pit                    |
| Fan operating  | Minimum speed 40 %, fan type WPA 07 / DM85         |
| Firing-up time | Range 30–120 min; MBtek value 120 min              |
| Kindling       | Enough to carry the load into ignition             |

→ [First firing](https://uni.sonicar.tech/docs/operation/first-firing)

## Boiler will not reach setpoint [#boiler-will-not-reach-setpoint]

| Cause                         | Fix                                                                    |
| ----------------------------- | ---------------------------------------------------------------------- |
| Fouled heat exchanger         | Brush the top of the heat exchanger. Soot and ash reduce heat transfer |
| Scale inside the water jacket | 1 mm of scale costs 10 % of heat transfer. Check fill water hardness   |
| Wet fuel                      | Oak at 50 % moisture carries a third of its dry value                  |
| Load larger than the boiler   | Check the heat loss calculation against 85–205 KBTU                    |
| Air leaks at door gaskets     | Inspect the sealing cord                                               |
| Fan speed too low             | Maximum 80 %                                                           |

## Fire goes out during supervision [#fire-goes-out-during-supervision]

| Setting                        | Adjustment             |
| ------------------------------ | ---------------------- |
| Fan performance in supervision | Raise from 35 %        |
| Pause between blowups          | Shorten from 5 min     |
| Purge time                     | Lengthen within 5–60 s |

**Too long a pause extinguishes the coals; too short and the boiler temperature rises too high.**

## Boiler overshoots setpoint [#boiler-overshoots-setpoint]

| Setting                | Adjustment          |
| ---------------------- | ------------------- |
| Purge time             | Shorten             |
| Pause between blowups  | Lengthen            |
| Fan slowdown threshold | Widen from 12 °C    |
| Boiler hysteresis      | Raise within 1–3 °C |

## Room is cold although the boiler is hot [#room-is-cold-although-the-boiler-is-hot]

| Cause                              | Check                                             |
| ---------------------------------- | ------------------------------------------------- |
| Room thermostat logic inverted     | Must **open** when satisfied, **close** on demand |
| CH pump pause time too long        | Range 0–240 min; factory default 1 min            |
| Pump start temperature not reached | 35 °C / 95 °F                                     |
| HUW priority stealing the heat     | Turn priority off, or cap HUW working hours       |
| Air in the emitters                | Vent                                              |

→ [Room thermostat control](https://uni.sonicar.tech/docs/controller/thermostat)

## Pressure keeps changing [#pressure-keeps-changing]

| Symptom                          | Cause                                    |
| -------------------------------- | ---------------------------------------- |
| Pressure falls over days         | Leak, or air being vented out            |
| Pressure rises sharply with heat | Expansion tank undersized or waterlogged |
| Pressure rises slowly when cold  | Fill valve passing                       |

Working pressure must not exceed **15 psi**; never allow above **36 psi**.

<SupportCta title="Still stuck?" />

<NextStep href="/docs/troubleshooting/alarm-codes" title="Alarm codes">
  The full controller alarm list in one table.
</NextStep>


# How the UNI 60 works (/docs/start/how-it-works)



**The UNI 60 burns a full firebox of wood slowly under fan-controlled air, then pulls the hot flue gas back through three heat-exchange passes before it reaches the chimney.** The controller modulates the fan to hold a target water — or exhaust gas — temperature, so one load can run for hours instead of burning out in one rush.

## The combustion path [#the-combustion-path]

<Figure src="/img/boiler/structure.png" alt="Sectional drawing of the UNI boiler showing the body, furnace, third flue-gas pass, chimney, grate, ash pan, doors, pipe connections, fan and controller, with airflow arrows" caption="<><b>Picture 1 — boiler structure.</b> Arrows marked 18 show the direction of air during combustion.</>" source="UNI Boiler Manual §6.0" width="1400" height="1153" />

The numbered callouts in the drawing map to these parts:

| # | Component          | #  | Component                          |
| - | ------------------ | -- | ---------------------------------- |
| 1 | Body               | 10 | Service flue gas door              |
| 2 | Furnace            | 11 | Supply pipe connection             |
| 3 | Flue gas 3rd pass  | 12 | Return pipe connection             |
| 4 | Chimney connection | 13 | Drain pipe                         |
| 5 | Grate set          | 14 | Temperature sensor well            |
| 6 | Support            | 15 | Fan                                |
| 7 | Ash pan            | 16 | Controller                         |
| 8 | Fuel loading door  | 17 | Ash door                           |
| 9 | Ash removal door   | 18 | Direction of air during combustion |

<Callout title="The ash pan sits outside the boiler">
  Unlike the drawing's internal position, the ash pan on delivered units goes **outside the unit, at
  the front of the ash door**.
</Callout>

### What happens on one load [#what-happens-on-one-load]

<Steps>
  <Step>
    **Loading.** Split wood goes in through the fuel loading door (8) onto the grate set (5). The UNI 60 firebox holds 58 gallons and takes logs up to 26 in long.
  </Step>

  <Step>
    **Ignition and firing up.** The controller runs the fan hard for the firing-up period to establish the fire quickly. In *Brager Expert exhaust gases* mode it holds the exhaust target at 300 °C during this window.
  </Step>

  <Step>
    **Controlled combustion.** The fan (15) forces air into the furnace along the path shown by arrows 18. Because air is metered rather than free, the load burns from the top or the bottom over many hours instead of all at once.
  </Step>

  <Step>
    **Three-pass heat extraction.** Flue gas leaves the furnace (2), turns through the flue gas passes and the third pass (3) above the firebox, giving up heat to the water jacket on the way, and exits through the chimney connection (4).
  </Step>

  <Step>
    **Supervision.** Once the water reaches setpoint the controller drops into supervision: the fan stops and only pulses briefly at a low speed to keep the coals alive without overheating the boiler.
  </Step>

  <Step>
    **Quenching.** When the fuel runs out — detected by falling water temperature or falling exhaust temperature — the controller stops the fan, lights the STOP indicator, and optionally stops the circulation pump.
  </Step>
</Steps>

## Inside the water jacket [#inside-the-water-jacket]

<Figure src="/img/boiler/section.png" alt="Three-dimensional cutaway of the UNI boiler showing water jacket, mineral wool insulation and steel plate thicknesses around the firebox and heat exchanger" caption="<><b>Boiler internal section view.</b> Water surrounds the firebox on all sides; mineral wool insulation sits between the water jacket and the outer casing.</>" source="UNI Boiler Manual, fire safety rating addendum" width="1105" height="1606" max="560" />

**Water wraps the firebox and the flue passes, and the whole assembly is wrapped again in mineral wool.** The plate thicknesses called out in the drawing range from ¼ in on the outer surfaces to 1½ in at the heaviest sections, which is what gives the boiler its thermal mass and its 1,224 lb weight.

The insulation and steel both carry fire safety classifications:

| Material                | Thickness | Class rating |
| ----------------------- | --------- | ------------ |
| Mineral wool insulation | 1½ in     | Class A1     |
| EN 10051/10 mild steel  | ¼ in      | Class A\*    |

<small>
  \* Subject to individual material tests. Class A materials have a flame spread index of 0–25 under ASTM E84 / E119.
</small>

## What the controller adds [#what-the-controller-adds]

**The TIS Tronic 260U turns a wood fire into a thermostatically controlled heat source.** It:

* drives the **fan** with variable speed, which is the only real throttle a wood boiler has;
* reads the **boiler water temperature** (`T1`) and, optionally, the **exhaust gas temperature** (`T3`);
* starts and stops the **central heating pump** (`Q3`) and the **domestic hot water pump** (`Q4`);
* responds to a **room thermostat** on `I2`;
* and is backed by an independent **STB bimetallic sensor** on `I1` that cuts the fan if the water passes roughly 90 °C, regardless of what the software is doing.

That last point matters: the safety chain is hardware, not firmware. See [Electrical and sensors](https://uni.sonicar.tech/docs/installation/electrical).

## Fuel flexibility [#fuel-flexibility]

**The UNI is a universal solid-fuel boiler — it runs on wood, coal, peat, woodchips and mulch.** Fuel choice changes both output and maintenance intervals: wood deposits more tar and soot in the chimney than coal, so wood-fired units need more frequent sweeping. Details are in [Fuel properties](https://uni.sonicar.tech/docs/operation/fuel).

<Callout type="error" title="Never burn waste">
  Burning waste, plastics or flammable liquids releases poisonous gases and will damage the boiler.
  Use recommended fuels only.
</Callout>

<NextStep href="/docs/start/specifications" title="Specifications">
  Every published figure for the UNI 60, plus the full UNI range for comparison.
</NextStep>


# Quick start (/docs/start/quick-start)



**A UNI 60 installation runs in eleven stages, and skipping any of the first eight will cost you later.** Use this page as the project checklist; each step links to the page that covers it in full.

<Callout type="warn" title="First firing is not a DIY step">
  Section 6.4 of the UNI boiler manual requires the first firings to be carried out by a trained
  installer or service technician. Electrical connections must be made by a qualified electrician.
</Callout>

<Steps>
  <Step>
    ### Confirm the boiler suits the building [#confirm-the-boiler-suits-the-building]

    Check the heat load against the UNI 60's **85–205 KBTU** output and **5,000 ft²** nominal coverage. Square-footage figures are approximate — real sizing depends on heat loss, insulation and climate.

    → [Specifications](./specifications.mdx)
  </Step>

  <Step>
    ### Inspect the delivery [#inspect-the-delivery]

    Check the boiler for shipping and mechanical damage **before** accepting it, and confirm every item on the packing list is present. After sale, the distributor will not accept claims for incompleteness or mechanical damage.

    → [What's in the box](./whats-in-the-box.mdx)
  </Step>

  <Step>
    ### Read the safety rules [#read-the-safety-rules]

    Pressure, temperature and fuel limits govern every later decision. Maximum operating pressure is **15 psi**, maximum flow temperature **185 °F**, and the boiler must never run without a relief valve.

    → [Safety](./safety.mdx)
  </Step>

  <Step>
    ### Lay out the boiler room [#lay-out-the-boiler-room]

    Set the clearances, the floor, and the service access before anything is moved into place. You need **36 in** at the front to clean the boiler and at least **24 in** behind it.

    → [Boiler room and clearances](https://uni.sonicar.tech/docs/planning/boiler-room)
  </Step>

  <Step>
    ### Size and specify the chimney [#size-and-specify-the-chimney]

    The flue must be at least the diameter of the boiler outlet — **8 in** for the UNI 60 — in acid-resistant stainless steel, insulated wherever it is exposed.

    → [Chimney requirements](https://uni.sonicar.tech/docs/planning/chimney)
  </Step>

  <Step>
    ### Design the hydronic system [#design-the-hydronic-system]

    Closed system, expansion tank, relief valve, return-temperature protection and — in almost every case — a buffer tank.

    → [System design](https://uni.sonicar.tech/docs/planning/system-design) · [Buffer tank and hot water](https://uni.sonicar.tech/docs/planning/buffer-and-hot-water)
  </Step>

  <Step>
    ### Position and pipe the boiler [#position-and-pipe-the-boiler]

    Set the boiler level on a non-combustible floor, connect **2 in** supply and return, fit the relief valve and drain, and connect the flue.

    → [Positioning](https://uni.sonicar.tech/docs/installation/positioning) · [Piping](https://uni.sonicar.tech/docs/installation/piping)
  </Step>

  <Step>
    ### Fill and pressure-test [#fill-and-pressure-test]

    Fill with clean water of **no more than 2 ppm hardness**, vent the system, and test. Maximum test pressure is **50 psi**.

    → [Filling and water quality](https://uni.sonicar.tech/docs/installation/filling)
  </Step>

  <Step>
    ### Wire the controller, sensors and pumps [#wire-the-controller-sensors-and-pumps]

    Boiler sensor into the immersion well, STB clamped to the supply, fan and pumps to their outputs, thermostat to `I2`. A 120 V pump needs the supplied 230 V relay block.

    → [Electrical and sensors](https://uni.sonicar.tech/docs/installation/electrical) · [Pump wiring](https://uni.sonicar.tech/docs/installation/pump-wiring)
  </Step>

  <Step>
    ### Load the recommended controller settings [#load-the-recommended-controller-settings]

    Apply the MBtek settings for the UNI 60 before the first fire — the factory defaults are generic and will not burn well in this boiler.

    → [Recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings)
  </Step>

  <Step>
    ### Fire it, then hand it over [#fire-it-then-hand-it-over]

    Check the draft, load the firebox, ignite, run **Start Fire**, and stay with the boiler. Then train the owner on loading, ash removal and the cleaning schedule.

    → [First firing](https://uni.sonicar.tech/docs/operation/first-firing) · [Maintenance schedule](https://uni.sonicar.tech/docs/maintenance/schedule)
  </Step>
</Steps>

## Settings cheat sheet [#settings-cheat-sheet]

**These are the MBtek-recommended UNI 60 values — set them at commissioning.** Full explanations are on the [recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings) page.

| Setting                                | Value                   |
| -------------------------------------- | ----------------------- |
| Boiler setpoint                        | 65 °C / 149 °F          |
| Exhaust setpoint                       | 160–240 °C / 320–464 °F |
| Maximum fan speed                      | 80 %                    |
| Minimum fan speed                      | 40 %                    |
| Fan performance in supervision         | 35 %                    |
| Fan ON (purge) time                    | 10 s                    |
| Fan OFF (pause) time                   | 5 min                   |
| Fan type                               | WPA 07 / DM85           |
| Boiler hysteresis                      | 2 °C / 5 °F             |
| Fan slowdown threshold                 | 12 °C / 21 °F           |
| Maximum boiler temperature             | 80 °C / 176 °F          |
| Boiler shutdown temperature            | 35 °C / 95 °F           |
| Pump start temperature                 | 35 °C / 95 °F           |
| Boiler cooling temperature             | 78 °C / 172 °F          |
| Firing-up time                         | 120 min                 |
| Brager Expert exhaust — firing-up time | 10 min                  |

<SupportCta title="Want a second pair of eyes on the plan?" />

<NextStep href="/docs/start/how-it-works" title="How the UNI 60 works">
  The combustion path, the three flue passes, and what the fan and controller actually do.
</NextStep>


# Safety (/docs/start/safety)



**The UNI 60 runs at up to 185 °F and 15 psi with an open fire inside it — the limits on this page are not advisory.** Read them before planning the installation, because several of them dictate how the system must be piped and wired.

<Callout type="error" title="Non-negotiable limits">
  * Maximum **operating** pressure: **15 psi**
  * Never allow pressure above **36 psi**
  * Maximum **test** pressure: **50 psi**
  * Maximum flow temperature: **185 °F / 85 °C**
  * **Never** use the appliance without a safety relief valve
  * **Never** start the boiler with no water, partial water, or frozen water in it
  * Do not leave the boiler filled with water at an ambient temperature below **+41 °F / +5 °C**
</Callout>

## Before installation [#before-installation]

**Commissioning of the boiler must be performed by a professional authorised by the manufacturer.** Boilers comply with safety requirements only if all the installation and operation requirements have been followed.

* Heating system design and installation must be done by a qualified professional.
* Electrical connections must be made by a **qualified electrician**.
* The boiler must be **electrically grounded**.
* The first firings must be carried out by a trained installer or service technician.
* Do not leave the boiler running unsupervised during the first firings after installation.

## In operation [#in-operation]

<Callout type="warn" title="Burn hazard">
  Opening the boiler doors during operation exposes you to very high temperatures. This can cause
  burns and can damage the lining and other parts of the boiler. Use personal protective equipment.
</Callout>

**Day-to-day rules:**

* Do not open the doors for a long time while the boiler is firing.
* Do not use flammable liquids to start the fire.
* Do not allow children to operate the boiler without adult supervision.
* Position the relief valve discharge drain so that it is safe if the valve opens.
* Do not operate the boiler without water, or only partially filled.
* Load fuel **before** combustion, not into a roaring fire.
* Turn the fan off before adding more fuel, then observe the precautions above.

<Callout type="warn" title="Backdraught on opening">
  Improper air supply adjustment can lead to heavy smoke and incomplete combustion. Combustion
  starved of air can ignite suddenly when the door is opened and air rushes in. Open doors slowly
  and stand to the side.
</Callout>

## Fuel safety [#fuel-safety]

**Use only recommended fuels: wood, coal, peat, woodchips and mulch.**

Burning waste, plastics or flammable liquids releases poisonous gases. If there is any danger of explosion or fire, or combustion gas or steam is escaping indoors — **stop the boiler**.

Do not stack fuel closer than **4 ft** to the boiler.

## Emergency procedure [#emergency-procedure]

**If there is a risk of explosion, ignition, gas contamination or fumes, stop the burning process in this order:**

<Steps>
  <Step>
    Turn off the power to the controller.
  </Step>

  <Step>
    Open the loading door, so that excess gas is not left waiting to combust.
  </Step>

  <Step>
    Put the fire out with **sand**.
  </Step>

  <Step>
    Remove the unburned fuel.
  </Step>

  <Step>
    Ventilate the room with fresh air.
  </Step>
</Steps>

Shut the boiler down in the event of any problem, and disconnect it from the mains before any repair, maintenance or cleaning.

## Electrical safety [#electrical-safety]

* The device is under **electric voltage**. Never work on pumps, fans or other connected devices while the controller is powered. Switch off the power and take measures against accidental switching on.
* Before starting the controller, measure the ground resistance of pump motors and the insulation resistance of the wiring.
* Incorrect wiring can destroy the controller.
* The controller must not be exposed to liquids or installed in a high-humidity room. Keep dirt and conductive dust out of it.
* Fit a **voltage stabiliser** of appropriate rating for reliable operation.
* During a thunderstorm, unplug the controller from the mains — lightning can destroy it.
* If there is any electrical fault — a short to the boiler body, deteriorating wire insulation — disconnect the boiler from the power supply immediately and call service.

<Callout title="If water gets into the controller">
  Disconnect it immediately, dry it with a hairdryer on **low** heat, wait 24 hours, then reconnect.
</Callout>

## The protection chain [#the-protection-chain]

**Three independent layers protect the UNI 60 from overheating, and only the first is software.**

| Layer                                   | Trigger                                       | Action                                                                                                                 |
| --------------------------------------- | --------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- |
| Controller — maximum boiler temperature | User setting, MBtek recommends 80 °C / 176 °F | External controls such as the room thermostat are ignored; fan control functions are disabled                          |
| Controller — emergency threshold        | 94 °C                                         | Alarm, boiler protection mode; all circulation pumps run                                                               |
| STB bimetallic sensor (hardware, `I1`)  | \~90 °C water                                 | Fan cut. Per EN 303-5:2012, the fan cannot restart until water drops below **60 °C** *and* the alarm is manually reset |

Optional DZT thermal protection sensors are available with different trip points:

| Sensor | Opens at       | Closes at      |
| ------ | -------------- | -------------- |
| DZT-1  | 185 °F / 85 °C | 140 °F / 60 °C |
| DZT-2  | 200 °F / 95 °C | 155 °F / 70 °C |

Both connect to terminal `I1`. Use a DZT-2 if you need to operate at a higher temperature.

## Regulatory basis [#regulatory-basis]

* The regulator must not be used on boilers in installations that do not comply with **PN-EN 303-5**.
* Chimneys must meet **EN 1856-1:2013** (metal chimney requirements, part 1) and **EN 1856-2:2013** (metal liners and connecting pipes).
* The controller is declared to **2014/35/EU** (LVD) and **2014/30/EU** (EMC), to standards PN-EN 60730-1:2012 and PN-EN 60730-2-9:2011.
* All installations must comply with applicable **local building codes**. Clearance requirements for solid-fuel appliances and stove pipe vary by region — consult local regulations or a certified building inspector, and keep documentation of clearance distances for insurance purposes.

<NextStep href="/docs/planning/boiler-room" title="Boiler room and clearances">
  Lay out the room: clearances, floor, service access and ventilation.
</NextStep>


# UNI 60 specifications (/docs/start/specifications)



**The UNI 60 delivers 85–205 KBTU into a hydronic system, heats up to 5,000 ft², holds 40 gallons of water and weighs 1,224 lb.** Every figure below comes from the current MBtek specification sheet, which supersedes the older factory manual where the two differ.

<SpecGrid
  items="[
  { label: 'Model', value: 'UNI 60' },
  { label: 'Capacity', value: '85–205 KBTU' },
  { label: 'Heat area', value: '5,000 ft²' },
  { label: 'Water volume', value: '40 gal' },
  { label: 'Firebox size', value: '58 gal' },
  { label: 'Log length', value: '26 in' },
  { label: 'Connection', value: '2 in' },
  { label: 'Chimney', value: '8 in' },
  { label: 'Width', value: '30 in' },
  { label: 'Depth', value: '36 in' },
  { label: 'Height', value: '65 in' },
  { label: 'Weight', value: '1,224 lb' },
]"
/>

## Performance and construction [#performance-and-construction]

| Property                   | Value                                           |
| -------------------------- | ----------------------------------------------- |
| Heat output                | 85–205 KBTU (25–60 kW)                          |
| Nominal heated area        | Up to 5,000 ft²                                 |
| Minimum efficiency         | 82 % (factory technical data)                   |
| Published efficiency       | 86 %+ guaranteed (MBtek, UNI series)            |
| Burn time                  | Up to 24 hours on a full load                   |
| Fuel types                 | Wood, coal, woodchips, peat, mulch              |
| Combustion                 | Forced draft, fan-controlled, three flue passes |
| Controller                 | TIS Tronic 260U                                 |
| Power supply               | 230 V / 50 Hz AC                                |
| Maximum operating pressure | 15 psi                                          |
| Maximum test pressure      | 50 psi                                          |
| Maximum flow temperature   | 185 °F / 85 °C                                  |
| Origin                     | Made in Europe                                  |

<Callout title="±5 % tolerance">
  The factory states that weight and dimensions may vary by ±5 %. Allow for that when planning
  doorways, floor loading and lifting equipment.
</Callout>

## The full UNI range [#the-full-uni-range]

**Use this table to sanity-check the model against the load — the UNI 60 sits in the middle of the range.**

<Figure src="/img/boiler/hero.webp" alt="MBtek UNI wood boiler unit" width="800" height="800" max="260" caption="UNI series boiler." />

| Boiler       | Unit | PRO 11 | PRO 30 | UNI 15 | UNI 40 | **UNI 60** | UNI 95  | UNI 150 | UNI 300  | UNI 500  | UNI 1000  |
| ------------ | ---- | ------ | ------ | ------ | ------ | ---------- | ------- | ------- | -------- | -------- | --------- |
| Capacity     | KBTU | 20–55  | 32–105 | 27–68  | 51–137 | **85–205** | 154–338 | 185–512 | 320–1000 | 545–1700 | 1000–3400 |
| Heat area    | ft²  | 1500   | 3000   | 2500   | 4000   | **5000**   | 8000    | 12000   | 22000    | 40000    | 78000     |
| Water volume | gal  | 12     | 12     | 21     | 30     | **40**     | 48      | 112     | 315      | 515      | 772       |
| Connection   | in   | 1½     | 1½     | 1½     | 1½     | **2**      | 2       | 2       | 3        | 3        | 4         |
| Chimney      | in   | 4      | 6      | 6      | 8      | **8**      | 8       | 8       | 12       | 12       | 16        |
| Firebox size | gal  | 9      | 28     | 25     | 44     | **58**     | 81      | 159     | 278      | 382      | 573       |
| Log length   | in   | 11     | 17     | 20     | 24     | **26**     | 30      | 48      | 66       | 88       | 132       |
| Width        | in   | 15     | 18     | 24     | 28     | **30**     | 30      | 30      | 39       | 39       | 58        |
| Depth        | in   | 22     | 28     | 25     | 34     | **36**     | 44      | 63      | 81       | 105      | 158       |
| Height       | in   | 45     | 55     | 55     | 55     | **65**     | 66      | 67      | 84       | 84       | 126       |
| Weight       | lb   | 400    | 590    | 716    | 992    | **1224**   | 1490    | 3200    | 5050     | 6800     | 8800      |

## Controller specification [#controller-specification]

**The TIS Tronic 260U is rated for 1 A per output and draws 4.5 W on its own.**

| Property                               | Value                                      |
| -------------------------------------- | ------------------------------------------ |
| Power                                  | 230 V / 50 Hz AC                           |
| Relative humidity                      | 30–75 %                                    |
| Ambient temperature                    | 5–40 °C / 41–104 °F                        |
| Fan output (`Q1`)                      | 1 A                                        |
| Central heating pump output (`Q3`)     | 1 A                                        |
| Hot water pump output (`Q4`)           | 1 A                                        |
| Power consumption, no external devices | 4.5 W                                      |
| Fuse                                   | 250 V, 3.15 A, 5 × 20 mm                   |
| Conformity                             | 2014/35/EU LVD, 2014/30/EU EMC, CE 05/2020 |

Full parameter ranges and defaults are in the [parameter reference](https://uni.sonicar.tech/docs/resources/parameter-reference).

## Sensors [#sensors]

| Sensor                   | Terminal | Wire length | Type       |
| ------------------------ | -------- | ----------- | ---------- |
| Boiler (CH) temperature  | `T1`     | 0.8 m       | KTY-81-210 |
| Domestic hot water (HUW) | `T2`     | 3 m         | KTY-81-210 |
| Exhaust gas              | `T3`     | —           | PT1000     |
| Safety thermostat (STB)  | `I1`     | 1 m         | Bimetal    |

<Callout type="warn" title="The exhaust sensor is sold separately">
  The PT1000 exhaust gas sensor is **not** included in the standard controller kit. Without it the
  boiler cannot run in *Brager Expert exhaust gases* mode — which is the mode MBtek recommends for
  the UNI 60.
</Callout>

<NextStep href="/docs/start/whats-in-the-box" title="What's in the box">
  The packing list, and what to check before you sign for the delivery.
</NextStep>


# What's in the box (/docs/start/whats-in-the-box)



**A UNI delivery contains the boiler assembly, the controller, the fan, the ash pan, a step-up transformer and a 220 VAC relay — and you must inspect all of it before you sign.** After the sale, the distributor will not accept claims for incompleteness or mechanical damage.

## Packing list [#packing-list]

| ID | Item                         | Qty |
| -- | ---------------------------- | --- |
| 1  | Boiler assembly              | 1   |
| 2  | Controller (TIS Tronic 260U) | 1   |
| 3  | Fan                          | 1   |
| 4  | Ash pan                      | 1   |
| 5  | Step-up transformer          | 1   |
| 6  | Relay 220 VAC                | 1   |
| 7  | Temperature gauge            | —   |

<Callout title="Why a transformer and a relay?">
  The controller and fan are 230 V devices. In North American installations the step-up transformer
  supplies them from a 120 V feed, and the 220 VAC relay block lets the 230 V pump outputs switch a
  120 V circulator. Wiring for that is on the [pump wiring](https://uni.sonicar.tech/docs/installation/pump-wiring) page.
</Callout>

## Inspect before you accept [#inspect-before-you-accept]

<Steps>
  <Step>
    ### Check the crate and the boiler body [#check-the-crate-and-the-boiler-body]

    Walk around the unit. Look for dents in the casing, damage to door faces, a bent flue collar, or a cracked controller housing. Photograph anything you find **before** unloading is complete.
  </Step>

  <Step>
    ### Confirm it travelled upright [#confirm-it-travelled-upright]

    The boiler must be transported on the vehicle **in the vertical position only**. A unit that arrived on its side should be recorded on the delivery paperwork.
  </Step>

  <Step>
    ### Count the loose items [#count-the-loose-items]

    Controller, fan, ash pan, transformer, relay. Missing items are far easier to resolve at delivery than a week later.
  </Step>

  <Step>
    ### Check the doors and gaskets [#check-the-doors-and-gaskets]

    Open each door. The sealing cord should be intact and seated. Door sealing cord is a consumable and is not covered by warranty, so a damaged cord found later becomes your cost.
  </Step>

  <Step>
    ### Note damage on the delivery documents [#note-damage-on-the-delivery-documents]

    Record any mechanical damage in writing at the time of delivery, and notify your distributor immediately.
  </Step>
</Steps>

<Callout type="warn" title="Aesthetic vs functional damage">
  The distributor is not responsible for cosmetic damage during shipping. Mechanical damage that
  impairs the use of the boiler — a broken handle or controller, for example — will be repaired or
  replaced.
</Callout>

## What you will also need [#what-you-will-also-need]

**None of the following ships with the boiler, and the installation cannot be completed without them.**

| Item                          | Why                                                                  | Covered in                                                       |
| ----------------------------- | -------------------------------------------------------------------- | ---------------------------------------------------------------- |
| Safety relief valve           | Mandatory — the boiler must never run without one                    | [Piping](https://uni.sonicar.tech/docs/installation/piping)                              |
| Expansion tank                | Required on both open and closed systems                             | [System design](https://uni.sonicar.tech/docs/planning/system-design)                    |
| Return-temperature protection | Keeps return water above \~130 °F to stop condensation and corrosion | [Piping](https://uni.sonicar.tech/docs/installation/piping)                              |
| Buffer tank                   | Absorbs the heat of a full burn the building cannot use yet          | [Buffer tank and hot water](https://uni.sonicar.tech/docs/planning/buffer-and-hot-water) |
| Circulation pump(s)           | Central heating, and hot water if fitted                             | [Pump wiring](https://uni.sonicar.tech/docs/installation/pump-wiring)                    |
| PT1000 exhaust gas sensor     | Needed for *Brager Expert exhaust gases* mode                        | [Electrical and sensors](https://uni.sonicar.tech/docs/installation/electrical)          |
| Chimney / flue system         | 8 in, acid-resistant stainless                                       | [Chimney requirements](https://uni.sonicar.tech/docs/planning/chimney)                   |
| Chimney brush and scraper     | Weekly cleaning in mid-winter                                        | [Cleaning](https://uni.sonicar.tech/docs/maintenance/cleaning)                           |

MBtek sells matched components — boiler station, thermostatic protection valve, DHW tank and the UNI remote control — on the [UNI 60 product page](https://mbtek.com/collections/wood-boilers/products/uni-60-boiler-200k-btu).

<NextStep href="/docs/start/safety" title="Safety">
  The pressure, temperature and fuel limits that govern every later step.
</NextStep>


# Contact MBtek (/docs/support/contact)



**MBtek can help with sizing, commissioning, controller settings, parts and warranty.** For anything that requires hands on the boiler, use the installer network.

## Get in touch [#get-in-touch]

<Cards>
  <Card title="Call 888-301-0737" href="tel:+18883010737" description="Talk to an MBtek specialist about sizing, system design or a boiler that isn't behaving." />

  <Card title="info@mbtek.com" href="mailto:info@mbtek.com" description="Email support — include your model, controller software version and what you have already tried." />

  <Card title="Find an installer" href="https://mbtek.com/find-an-installer" description="Independent contractors familiar with MBtek products. They are not MBtek employees, but they know these boilers." />

  <Card title="Contact MBtek" href="https://mbtek.com/contact" description="Product questions, sizing guidance and next steps." />
</Cards>

## Address [#address]

**MBtek**
2411 N. American Street
Philadelphia, PA 19133, USA

[mbtek.com](https://mbtek.com) · [888-301-0737](tel:+18883010737) · [info@mbtek.com](mailto:info@mbtek.com)

## Buy and configure [#buy-and-configure]

<Cards>
  <Card title="UNI 60 product page" href="https://mbtek.com/collections/wood-boilers/products/uni-60-boiler-200k-btu" description="Pricing, companion products and customer installations." />

  <Card title="All wood boilers" href="https://mbtek.com/collections/wood-boilers" description="The full UNI, TITAN Lambda and PRO ranges." />

  <Card title="System Builder" href="https://mbtek.com/system-builder" description="Put the boiler, tank, station and controls together as a system." />
</Cards>

## What to have ready before you call [#what-to-have-ready-before-you-call]

**Support calls go much faster with these to hand:**

| Item                           | Where to find it                                                              |
| ------------------------------ | ----------------------------------------------------------------------------- |
| Boiler model and serial number | Data plate on the boiler                                                      |
| Controller software version    | Controller menu → Software version                                            |
| Current controller settings    | Compare against [recommended settings](https://uni.sonicar.tech/docs/controller/recommended-settings) |
| Any alarm shown                | Press `F` for the alarm list                                                  |
| Fuel type and moisture         | See [Fuel properties](https://uni.sonicar.tech/docs/operation/fuel)                                   |
| System layout                  | Buffer tank, pumps, zones, return protection                                  |
| Commissioning date             | The warranty card                                                             |

## Companion products [#companion-products]

The UNI 60 is designed to work with:

| Product                     | What it does                                                                                                                   |
| --------------------------- | ------------------------------------------------------------------------------------------------------------------------------ |
| **Boiler station**          | Pump, thermostatic valve and thermometer in one insulated assembly — return-temperature protection, circulation and monitoring |
| **Boiler protection valve** | Thermostatic valve that keeps return water above 130 °F to reduce condensation and corrosion                                   |
| **APOLLO DHW80**            | Combined buffer and indirect tank — stores boiler heat and supplies household hot water                                        |
| **UNI Remote Control**      | Connects compatible TIS controllers to Brager Connect for remote monitoring, alarms and adjustments                            |

## Escalation path [#escalation-path]

<Steps>
  <Step>
    ### Check this documentation [#check-this-documentation]

    [Common problems](https://uni.sonicar.tech/docs/troubleshooting/common-problems) and [Alarm codes](https://uni.sonicar.tech/docs/troubleshooting/alarm-codes) cover the faults that actually happen.
  </Step>

  <Step>
    ### Call MBtek [#call-mbtek]

    888-301-0737 for sizing, settings and diagnosis.
  </Step>

  <Step>
    ### Involve your installer [#involve-your-installer]

    Anything requiring work on the boiler, the pipework or the electrics.
  </Step>

  <Step>
    ### Warranty claim [#warranty-claim]

    Report faults **immediately and in writing** to the distributor for your region. See [Warranty](./warranty.mdx).
  </Step>
</Steps>

<SupportCta title="Talk to MBtek" />


# Frequently asked questions (/docs/support/faq)



**The questions owners and installers ask most often, answered from the official documentation.** Each answer links to the page that covers it in depth.

## Where to go next [#where-to-go-next]

<Cards>
  <Card title="Sizing and specifications" href="/docs/start/specifications" description="Full UNI 60 figures and the whole range side by side." />

  <Card title="Does it need a buffer tank?" href="/docs/planning/buffer-and-hot-water" description="Why storage matters, and how to size it." />

  <Card title="Controller settings" href="/docs/controller/recommended-settings" description="The exact values MBtek specifies for the UNI 60." />

  <Card title="Something is wrong" href="/docs/troubleshooting/common-problems" description="Symptom-first diagnosis for the faults that actually happen." />

  <Card title="Maintenance" href="/docs/maintenance/schedule" description="Daily, weekly, mid-winter and seasonal tasks." />

  <Card title="Warranty" href="/docs/support/warranty" description="What is covered, for how long, and what voids it." />
</Cards>

<SupportCta title="Question not answered here?" />

<NextStep href="/docs/support/warranty" title="Warranty">
  What is covered, for how long, and what voids it.
</NextStep>


# Warranty (/docs/support/warranty)



**The boiler body is covered for 10 years on a closed system and 3 years on an open one — the difference is the single biggest warranty decision you will make.** The manufacturer provides a full guarantee of the product according to the warranty inclusions below.

<Callout type="warn" title="Fill in the warranty card">
  Warranty is only valid with a properly filled warranty card showing the **date of commissioning by
  the qualified installer**. Demand from your distributor and commissioning professional that the
  warranty card is correctly filled in.
</Callout>

## Warranty periods [#warranty-periods]

| Component                                        | Period                                                                        |
| ------------------------------------------------ | ----------------------------------------------------------------------------- |
| Boiler body, **closed** heating systems          | **10 years**                                                                  |
| Boiler body, **open** heating systems            | **3 years**                                                                   |
| Controller                                       | 1 year                                                                        |
| Fan                                              | 1 year                                                                        |
| TIS Tronic controller (manufacturer's own terms) | 24 months from date of sale, not more than 36 months from date of manufacture |

## What is covered [#what-is-covered]

* The manufacturer provides a guarantee on the manufactured product.
* The manufacturer is liable under warranty **only if a defect is found in the device itself**.
* The manufacturer decides whether to correct the defect or replace the unit.
* **Warranty repairs are free of charge.**
* Warranty covers only a device installed in accordance with the instructions and rules specified in them.

## What is not covered [#what-is-not-covered]

<Accordions>
  <Accordion title="Consumable material">
    Sealing cord (door gaskets), cast iron grate, handles, bolts, nuts, brush, scraper.
  </Accordion>

  <Accordion title="Controller fuse">
    Fuse failure is not covered by warranty.
  </Accordion>

  <Accordion title="Scale damage">
    Damage to the boiler due to the formation of scale is not covered. Fill water must be no more than 2 ppm hardness — see [Filling and water quality](https://uni.sonicar.tech/docs/installation/filling).
  </Accordion>

  <Accordion title="Aesthetic shipping damage">
    The distributor is not responsible for aesthetic appearance damage including during shipping. Mechanical damage that impairs the usage of the boiler — a broken handle or controller, for example — will be replaced or repaired accordingly.
  </Accordion>

  <Accordion title="Mechanical impact and misuse of the controller">
    Any mechanical impact — scratches, dents, ingress of moisture or other substances on the body or inside the regulator — incorrect use inconsistent with the instruction manual, self-repair, modification or design changes, and damage to the case, wires, cables or sensors made by the client or user.
  </Accordion>
</Accordions>

## What voids the warranty [#what-voids-the-warranty]

<Callout type="error" title="Warranty stops in case of wrong installation or improper use of the device">
  Specifically:

  * **Open heating systems.** If using the boiler in an open heating system the corrosion rate will be very fast and the warranty is avoided.
  * **Commissioning by a non-accredited person.** Commissioning must be performed by a professional authorised by the manufacturer — an accredited installer, service centre or representative. In case of non-compliance with these instructions the guarantee will not be effective and warranty claims will not be accepted.
  * **Unauthorised controller work.** Unauthorised activation, making changes to the device and repairs may cause deterioration of the boiler's operating parameters and its safety, and lead to loss of the guarantee for both the regulator and the boiler as a whole.
  * **Boilers not electrically grounded.** Boilers TIS UNI must be electrically grounded.
</Callout>

## Making a claim [#making-a-claim]

<Steps>
  <Step>
    ### Report immediately, in writing [#report-immediately-in-writing]

    Each complaint should be immediately transmitted after fault detection, **in writing**, by contacting the distributor of your region.
  </Step>

  <Step>
    ### Clean the equipment [#clean-the-equipment]

    At the time of performing a warranty repair by the service professional or distributor, the equipment must be cleaned of soot, tar and other contaminants.
  </Step>

  <Step>
    ### Provide access [#provide-access]

    The customer undertakes to provide all facilities and access to perform warranty and post-warranty repairs.
  </Step>

  <Step>
    ### Use an accredited repairer [#use-an-accredited-repairer]

    Warranty repairs can only be performed by a specialised organisation — the installer, service centre or distributor accredited by the manufacturer.
  </Step>
</Steps>

### Controller warranty claims [#controller-warranty-claims]

The controller is manufactured by **BelKomin LLC**. Under its own terms:

* Defects found during the warranty period are eliminated free of charge.
* The warranty covers malfunctions caused by defective parts and/or manufacturing defects.
* Defective equipment must be sent by the applicant — **after receiving the consent of the guarantor** — to the service institution. Parcels sent cash-on-delivery will not be accepted.
* Carefully check the damaged equipment, describe the type of damage in the warranty repair certificate, and deliver the damaged equipment with the warranty card to the plant's service department.
* The manufacturer decides independently whether to repair or replace the device. The period for correcting defects cannot exceed **14 working days**, and not less than 6 working days from the date the equipment arrives at the service centre.

Warranty claims and questions about the regulator should be directed to the seller, the seller's service department, or the manufacturer.

<SupportCta title="Warranty questions" />

<NextStep href="/docs/support/contact" title="Contact MBtek">
  Phone, email, installers and where to buy parts.
</NextStep>