BoilerFaultCodes BC High
Boiler Fault Code BC
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code BC appears across 2 boiler brands and 8 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has shut down because it is not burning fuel efficiently or safely, which is usually caused by a faulty internal sensor or an incorrect gas mixture. (As reported on Worcester Bosch Greenstar Utility 18/25)
Pick your boiler brand for the BC fix
Source
Information for the BC 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