BoilerFaultCodes CM120 Low
Boiler Fault Code CM120
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code CM120 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning This code is simply an information message indicating the current status of your heating timer or thermostat settings, not a system fault. (As reported on Baxi 400 Combi 2)
Pick your boiler brand for the CM120 fix
Source
Information for the CM120 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