Boiler Fault Code AA 0033

Also written as AA0033 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code AA 0033 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 that the water inside the heating system has become dangerously hot and has shut itself down to prevent damage or safety risks. (As reported on Ariston Clas One)