BoilerFaultCodes AA 7755 Emergency
Boiler Fault Code AA 7755
Also written as AA7755 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code AA 7755 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 an issue with the system that removes waste gases, meaning it has shut down to ensure your home remains safe. (As reported on Ariston Clas One)
Pick your boiler brand for the AA 7755 fix
Source
Information for the AA 7755 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