BoilerFaultCodes 424 High
Boiler Fault Code 424
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 424 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 detected that the internal temperature sensors have been wired or installed in the wrong positions, preventing it from heating safely. (As reported on Ideal Ideal Classic SE15P FF)
Pick your boiler brand for the 424 fix
Source
Information for the 424 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