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Heating engineer · Brussels and Wallonia
No heating: the boiler won't start
The radiators stay cold and the boiler won't fire: blank display, red light or an error code. The cause is often simple. A few safe checks will tell you within five minutes.
The most common causes
No power
A power cut, a tripped breaker or a blown fuse: the boiler's display is then blank.
Pressure too low
Below about 1 bar, the boiler protects itself and won't start.
The thermostat isn't calling for heat
Flat batteries, night or holiday programme, or a setting lower than the room temperature.
No gas or oil
Gas tap closed, meter turned off, or an almost empty oil tank.
A lockout
After a failed ignition or overheating, the boiler stops and shows a code.
A faulty part
Ignition, circuit board, pump or sensor: that needs an engineer.
What you can check yourself
- Display blank? Check the boiler's plug or switch, then the breaker in your fuse box.
- A code on the display? Write it down: it tells you what happened (see the error codes below).
- Check the pressure gauge: between 1 and 2 bar with the boiler cold is normal. Lower? Top it up (guide below).
- Thermostat: replace the batteries, check the programme and turn it up a few degrees.
- Gas: check that the tap under the boiler is open and that your gas cooker works, if you have one. Oil: check the tank gauge.
- If all is fine, reset once (guide below) and give the boiler a minute.
Don't
- Resetting again and again: if the code comes back, the boiler is reporting a real problem.
- Opening the boiler's casing.
- Smell gas? Don't touch anything and follow our « Smell of gas » page.
Call us if…
- The code comes back after a reset.
- The display stays blank even though there's power.
- The boiler starts, then stops after a few minutes.
- These checks don't reveal the cause.
What does a repair cost?
Call-out and diagnosis: €125 excl. VAT. The repair is extra, and you get its price before we start. We usually come within 24 hours (working days) and let you know 1 hour before we arrive.
This advice applies to most boilers. Every appliance has its quirks: if in doubt, your own manual applies, and we're happy to answer on the phone.
Frequently asked questions
My boiler won't come back on after a power cut: what should I do?
First check the breaker and the boiler's plug. If the display shows a code, a single reset is often enough. If it won't restart, call us: a power cut can damage the circuit board.
Who do I call when the boiler won't start?
A heating engineer who knows your brand. We repair gas and oil boilers in Brussels and across Wallonia: describe the fault by phone, on WhatsApp or with the form, photos included.
Find out more
A breakdown, a question? Get in touch.
Call us or message us on WhatsApp. Or leave your number, with a photo of the boiler if you like: we'll call you back.
