BoilerFaultCodes AM040 Medium
Boiler Fault Code AM040
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code AM040 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 Your boiler is struggling to accurately measure the temperature of the hot water it is producing, which may cause your taps to run cold or fluctuate in temperature. (As reported on Baxi 400 Combi 2)
Pick your boiler brand for the AM040 fix
Source
Information for the AM040 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