Boiler Fault Code Pilot On light on

Also written as PILOTONLIGHTON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code Pilot On light on appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is signalling that the internal starter flame is active, but if the boiler isn't firing up, it means the main burner hasn't received the signal to fully ignite. (As reported on Baxi Solo PF)