Safety
The hard limits for the UNI 60 — 15 psi maximum operating pressure, 185 °F maximum flow temperature, mandatory relief valve — plus emergency procedures and burn hazards.
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.
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
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
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.
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.
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.
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
If there is a risk of explosion, ignition, gas contamination or fumes, stop the burning process in this order:
Turn off the power to the controller.
Open the loading door, so that excess gas is not left waiting to combust.
Put the fire out with sand.
Remove the unburned fuel.
Ventilate the room with fresh air.
Shut the boiler down in the event of any problem, and disconnect it from the mains before any repair, maintenance or cleaning.
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.
If water gets into the controller
Disconnect it immediately, dry it with a hairdryer on low heat, wait 24 hours, then reconnect.
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
- 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.
Lay out the room: clearances, floor, service access and ventilation.
Frequently asked questions
What's in the box
The UNI 60 delivery contents, the damage inspection you must complete before accepting the boiler, and the parts you need to buy separately.
Boiler room and clearances
Required clearances for the UNI 60 — 24 in to side and back walls, 36 in at the front, 28 in overhead — plus floor, ventilation and service access requirements.