Boiler Fault Code Flame on before gas valve on

Also written as FLAMEONBEFOREGASVALVEON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026

Fault code Flame on before gas valve on appears across 2 boiler brands and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected a flame when there shouldn't be one, which means the internal sensors or ignition parts are sending incorrect signals to the control board. (As reported on Ideal Logic Max Heat 2)