BoilerFaultCodes FB365 Emergency
Boiler Fault Code FB365
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code FB365 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 has detected a potential internal gas leak during its safety checks and has shut down to keep your home safe. (As reported on Worcester Bosch Greenstar Si Combi / i System)
Pick your boiler brand for the FB365 fix
Source
Information for the FB365 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