Why does my boiler fire up then cut out after a few seconds?

This is usually a flame detection fault — the boiler lights but the flame sensor doesn't detect the flame and shuts the boiler down as a safety measure. Common causes include a dirty or faulty flame sensor, ignition electrode fault, or gas valve issue. Call FE Maintenance on 020 8445 1303.

Why does my boiler keep cutting out in cold weather?

In cold weather, the most likely cause is a frozen condensate pipe. This is the white plastic pipe that exits through an outside wall. Pour warm water on it and press the reset button. If it keeps happening, the pipe needs insulating — FE Maintenance can do this during a service.

Is it safe to keep resetting a boiler that keeps cutting out?

No — you should only reset once or twice. If the boiler keeps cutting out, it's doing so as a safety measure because it has detected a fault. Repeatedly resetting can mask a dangerous problem and potentially damage components. Call a Gas Safe engineer.

Can low gas pressure cause my boiler to keep cutting out?

Yes — if your gas pressure is too low, the boiler won't get enough gas to maintain the flame and will cut out. Check if other gas appliances work normally. If your gas hob also has a weak flame, call National Gas on 0800 111 999. If it's just the boiler, call FE Maintenance.

How quickly can FE Maintenance fix a boiler that keeps cutting out?

We offer same-day appointments across North, West and Central London. In most cases we can diagnose and fix the fault in a single visit. Call 020 8445 1303 before noon for a same-day appointment.

Boiler Keeps Switching Off? Causes & Fixes

🔍 Why Does My Boiler Keep Switching Off?

Cause	Symptoms	Fix
Low water pressure	Pressure below 1 bar, boiler cuts out	Repressurise system
Faulty thermostat	Boiler fires then cuts out quickly	Replace thermostat
Frozen condensate pipe	Cuts out in cold weather	Thaw pipe, reset
Blocked flue	Boiler locks out, error code	Engineer required
Faulty pump	Boiler overheats and cuts out	Engineer required
Airlocks in system	Boiler fires then cuts out	Bleed radiators
PCB fault	Random cutouts, error codes	Engineer required

✅ Check These Yourself First

Step 1 — Check the pressure

Look at the pressure gauge on the front of the boiler. It should read between 1.0 and 1.5 bar. If it's below 1, repressurise using the filling loop.

Step 2 — Check the thermostat

Make sure your room thermostat is set above the current room temperature. If it's a wireless thermostat, replace the batteries.

Step 3 — Check for error codes

Most modern boilers display a fault code when they lock out. Note the code and search our error code guides for Worcester Bosch or Vaillant.

Step 4 — Try a reset

Press the reset button once. If the boiler fires up and then cuts out again within 10 minutes, don't keep resetting — call an engineer.

Never reset a boiler more than twice. Repeated resets can damage the gas valve and turn a minor fault into an expensive repair.

💷 How Much Does It Cost to Fix?

Repair	Rough price
Low pressure or condensate fix	£80 – £150
Sensor, thermostat or ignition part	£100 – £250
Diverter valve, fan or pump	£150 – £350
Gas valve or circuit board (PCB)	£200 – £550
Heat exchanger	£300 – £700

Rough guide for London, parts and labour. The exact price depends on your boiler and the part. Our engineer gives you a fixed price after seeing the boiler, before any work starts. No VAT added.

Frequently Asked Questions

📚 Related Guides

Boiler not working guide Worcester Bosch error codes Boiler pressure low fix

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