BoilerFaultCodes A77 High
Boiler Fault Code A77
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code A77 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's internal computer is receiving an unexpected temperature reading from a sensor, which has caused it to stop working for safety reasons. (As reported on Vokera Compact A)
Pick your boiler brand for the A77 fix
Source
Information for the A77 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 7 July 2026