6 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Greenstar 24i
This boiler uses indicator light combinations
Note which lights are on, off, or flashing and at what speed. Match the combination to the cards below. Do not reset until you have noted the pattern. How to read fault codes →
Tap any card for details
Your boiler has detected an internal sensor failure and has stopped working to prevent damage or overheating.
Your boiler has detected a problem with one of its internal temperature sensors and has stopped working as a safety precaution.
Your boiler has detected an issue with the internal fan or the way it clears exhaust gases, so it has shut down to keep you safe.
Your boiler has failed to start up or stay burning, so it has purposefully shut itself off to prevent gas from building up.
Your boiler has completely lost power and is unable to turn on, likely due to a blown fuse or a failure in the electrical control board.
Your boiler has detected that it got too hot and has automatically shut itself down to prevent damage or fire risk.
BoilerFaultCodes