Boiler Fault Code Flame On Before Gas On

Also written as FLAMEONBEFOREGASON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code Flame On Before Gas On appears across 2 boiler brands 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 incorrectly thinks it sees a flame before it has even started the ignition process, which is a safety error that prevents it from starting up. (As reported on Ideal Logic Max Heat 2)