Boiler Fault Code Flame On Before Gas Valve On

Also written as FLAMEONBEFOREGASVALVEON — same fault.

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

Fault code Flame On Before Gas Valve On appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's safety system has detected a flame signal when there shouldn't be one, which prevents the unit from starting up for safety reasons. (As reported on Ideal Logic Code Combi ESP1)