BoilerFaultCodes ALL 11 High
Boiler Fault Code ALL 11
Also written as ALL11 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALL 11 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 has lost the electrical connection to the valve that controls the gas supply, meaning it cannot safely start up to provide heat or hot water. (As reported on Sime Murelle Advanced HE MkII Combi)
Pick your boiler brand for the ALL 11 fix
Source
Information for the ALL 11 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