BoilerFaultCodes Section M High
Boiler Fault Code Section M
Also written as SECTIONM — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Section M 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 switched itself off because the exhaust gases have become too hot, which is a safety measure to prevent damage to the system. (As reported on Baxi System)
Pick your boiler brand for the Section M fix
Source
Information for the Section M 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