BoilerFaultCodes L01 High
Boiler Fault Code L01
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code L01 appears across 2 boiler brands and 4 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 internal sensors have detected it is getting too hot, which is a safety measure to prevent damage. (As reported on Ideal Logic Code Combi ESP1)
Pick your boiler brand for the L01 fix
Source
Information for the L01 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