BoilerFaultCodes FA9 High
Boiler Fault Code FA9
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code FA9 appears across 1 boiler brand and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's internal communication system has lost power, meaning the different components cannot talk to each other to start the heating process. (As reported on Glow-worm Energy)
Pick your boiler brand for the FA9 fix
Source
Information for the FA9 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