BoilerFaultCodes ALL 81 Emergency
Boiler Fault Code ALL 81
Also written as ALL81 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALL 81 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 has detected an issue with the burning process during startup and has safely shut itself down to prevent any unsafe operation. (As reported on Sime Murelle Advanced HE MkII Combi)
Pick your boiler brand for the ALL 81 fix
Source
Information for the ALL 81 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