A05 High

Boiler Fault Code A05

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code A05 appears across 4 boiler brands and 19 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has stopped working because its internal fan, which safely exhausts gases, is not communicating correctly with the main control board. (As reported on Ferroli Modena HE)

Pick your boiler brand for the A05 fix

Ariston A05 7 models Ferroli A05 10 models Potterton A05 1 model Vokera A05 1 model

Source

Information for the A05 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