BoilerFaultCodes LC4 High
Boiler Fault Code LC4
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code LC4 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 has detected an internal electrical communication problem with the system that controls the pump and fan, meaning the unit cannot run safely. (As reported on Ideal HP290)
Pick your boiler brand for the LC4 fix
Source
Information for the LC4 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