How much does it cost to fix boiler error code ALL 40?

Typical repair cost for the boiler ALL 40 fault is £120-250 including labour.

ALL 40 High

Boiler Fault Code ALL 40

Also written as ALL40 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code ALL 40 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 detected that the electricity supply coming from your home's mains is unstable or at the wrong frequency, preventing it from starting safely. (As reported on Sime Murelle Advanced HE MkII Combi)

Pick your boiler brand for the ALL 40 fix

Sime ALL 40 3 models

Source

Information for the ALL 40 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