G High

Boiler Fault Code G

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code G appears across 4 boiler brands and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's burner is staying switched on even when no heating or hot water has been requested, which usually points to an internal control board issue. (As reported on Worcester Bosch 24i / 28i Junior)

Pick your boiler brand for the G fix

Ariston G 1 model Baxi G 5 models Main G 1 model Worcester Bosch G 2 models

Source

Information for the G 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 31 August 2026