BoilerFaultCodes 77 + High
Boiler Fault Code 77 +
Also written as 77 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 77 + appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's electronic control system is sending the wrong signals to the internal gas valve, causing the unit to shut down for safety. (As reported on Biasi Antares System)
Pick your boiler brand for the 77 + fix
Source
Information for the 77 + 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