BoilerFaultCodesThe 6 most common faults
Your boiler has detected a fault and has locked itself out to prevent damage or unsafe operation.
Locate the reset button (usually marked with a flame or 'R' symbol) on the control panel.Press and hold the reset button for five seconds, then release.Wait 2 minutes for the boiler to restart; if the red light returns, call a Gas Safe engineer.
Your boiler has failed to ignite and cannot produce heat, which is usually due to an interrupted gas supply, a blocked condensate pipe, or a component failure.
Check if other gas appliances in your home, like a hob, are working to confirm your gas supply is on.If it is freezing outside, check if the white plastic condensate pipe leading outdoors is frozen and thaw it with warm water.Press the reset button (usually marked with a flame or 'reset') and hold for five seconds.
Your boiler has likely lost pressure or is struggling to circulate water, which has caused it to stop running for safety.
Check the pressure gauge on the boiler or under the sink; it should be between 1 and 1.5 bar.If the pressure is low, use the filling loop valves to top the system up until the needle is in the green zone.Turn the selector knob to 'Reset' for five seconds, then turn it back to the original position.
Your boiler has lost power or is experiencing a total electronics failure, meaning it cannot operate or tell you what is wrong.
Check if your main consumer unit (fuse box) has tripped and reset it.Verify the boiler's fused spur switch is turned on and the fuse has not blown.Check if other appliances in your home have power to rule out a general power cut.
Your boiler has detected that the water temperature is rising far too quickly, often because water isn't flowing through the system as it should.
Ensure all radiator valves and lockdowns are fully openCheck that the boiler pressure is between 1.0 and 1.5 barGently restart the boiler using the reset button
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.
on the Glow-worm HXi
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