BoilerFaultCodesThe 6 most common faults
Your boiler has temporarily stopped working because the water pressure inside the system has dropped too low.
Locate the filling loop valves underneath your boiler.Open both valves gently to let water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both valves tightly and reset the boiler.
Your boiler has automatically shut down because it detected that the internal temperature has become too high, preventing it from overheating.
Check that your radiator valves are fully open to allow water to flow.Ensure there is no air trapped in the system by bleeding your radiators.Press the reset button (indicated by a flame with a cross through it) to restart the boiler.
Your boiler has switched itself off because the water inside it is heating up too quickly, which usually means the water isn't flowing through the system properly.
Check that all radiator valves are fully openEnsure the boiler pressure is between 1.0 and 1.5 bar on the gaugeTry resetting the boiler to see if the fault clears
Your boiler is unable to measure the temperature of the water inside it, so it has safely shut down to prevent overheating.
Full guide for F.00Your boiler is struggling to accurately measure the temperature of the water returning to it, so it has stopped working to prevent potential overheating.
Full guide for F.01Your boiler has stopped working because it is unable to accurately measure the temperature of the water flowing through the system due to a faulty electrical connection or sensor.
Full guide for F.10on the Glow-worm SUSTAIN 35c
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Glow-worm shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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