BoilerFaultCodes Main burner will not light High
Boiler Fault Code Main burner will not light
Also written as MAINBURNERWILLNOTLIGHT — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Main burner will not light appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is failing to ignite the flame needed to heat your water, which could be caused by blocked gas flow or a worn internal component. (As reported on Worcester Bosch WR325 RSF)
Pick your boiler brand for the Main burner will not light fix
Source
Information for the Main burner will not light fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026