A01 High

Boiler Fault Code A01

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code A01 appears across 5 boiler brands and 29 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has failed to ignite, meaning it cannot create the flame needed to provide you with heating or hot water. (As reported on Potterton Powermax HE)

Pick your boiler brand for the A01 fix

Ariston A01 13 models Ferroli A01 12 models Johnson Starley A01 1 model Potterton A01 2 models Vokera A01 1 model

Source

Information for the A01 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