BoilerFaultCodes An High
Boiler Fault Code An
Also written as AN — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code An 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 struggling to light or detect a steady flame, which means it has shut down as a safety precaution. (As reported on Biasi Inovia 2020)
Pick your boiler brand for the An fix
Source
Information for the An 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