🏠 Home Repairs
How to Fix a Boiler That Is Not Working
Before calling a Gas Safe engineer, there are several checks you can safely do yourself. Many boiler issues are caused by simple things like low pressure or a tripped switch.
Likely causes
- Low boiler pressure (most common cause)
- Pilot light has gone out
- Frozen condensate pipe
- Power or electrical fault
- Faulty thermostat settings
Step-by-step fix
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1
Check the boiler pressure
Look at the pressure gauge on the front of the boiler. It should read between 1 and 1.5 bar. If below 1, the system needs repressurising.
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2
Repressurise the boiler
Find the filling loop (a flexible silver hose under the boiler). Slowly open both valves until the pressure reaches 1.5 bar, then close both. The process is described in your boiler manual.
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3
Check the thermostat
Make sure the thermostat is set above the current room temperature and the timer is correctly programmed.
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4
Reset the boiler
Most modern boilers have a reset button (often a red button or a reset option in the display menu). Hold it for 3 seconds. Allow 5 minutes for the boiler to restart.
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5
Check for a frozen condensate pipe
In very cold weather the condensate pipe (a white plastic pipe usually exiting through an outside wall) can freeze. Pour warm (not boiling) water over the frozen section.
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6
Call a Gas Safe engineer
If none of the above works, call a Gas Safe registered engineer. It is illegal to work on gas appliances without Gas Safe registration. Find one at gassaferegister.co.uk.