Boiler not working? Checks to try before you call an engineer

No heating or hot water? A few safe checks often get a boiler going again. If they don’t, a Gas Safe registered engineer can find the fault.

If you smell gas

Don’t use light switches or flames. Open doors and windows, turn the gas off at the meter if you can, leave the property and call the National Gas Emergency line on 0800 111 999. It’s free and open 24 hours.

Safe checks you can do yourself

1
Check it has power
Is the boiler’s display or light on? If not, check the switch on the wall next to it and look for a tripped switch in your fuse box.
2
Check the timer and thermostat
A power cut or the clocks changing can reset the timer. Make sure the heating is set to come on now, and turn the room thermostat up a few degrees.
3
Check the pressure
Most combi boilers should read between 1 and 1.5 bar when the heating is off. If it’s below 1, the boiler may shut itself off. Your boiler’s manual shows how to top it up. If the pressure keeps dropping, there may be a leak, so book an engineer.
4
Look for a frozen condensate pipe
In freezing weather, the thin plastic pipe that runs from the boiler to a drain outside can freeze, and the boiler stops with an error code or a gurgling noise. Pour warm water, not boiling, along the pipe, then reset the boiler.
5
Reset it once
If the boiler shows an error code, look it up in the manual and press reset once. If it locks out again, stop resetting it and book an engineer.
6
Check the gas is on
Does your hob light? If you have a prepayment meter, check it has credit. If no gas appliance works and the meter has credit, call the National Gas Emergency line on 0800 111 999.

What to leave to an engineer

Never take the cover off a boiler or try to repair the gas parts yourself. By law, only a Gas Safe registered engineer can work on gas appliances, and every engineer carries a Gas Safe ID card you can check online.

Relay only sends Gas Safe registered engineers, and you see the price before you book: £95 including the first hour, then £80 an hour on weekdays, or £160 for the first hour, then £110 an hour for urgent help in the evenings and at weekends.

Check an engineer on the Gas Safe Register

Stopping it happening again

Have your boiler serviced once a year. A boiler service with Relay is a fixed £119.
Keep an eye on the pressure gauge, especially after bleeding radiators.
Run the heating for a short while in summer so parts don’t seize.