BoilerFaultCodes LED4 (Permanent) Low
Boiler Fault Code LED4 (Permanent)
Also written as LED4PERMANENT — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code LED4 (Permanent) appears across 1 boiler brand and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is correctly operating in heating mode, and the light indicates that your central heating system is currently active. (As reported on Ferroli Falcon)
Pick your boiler brand for the LED4 (Permanent) fix
Source
Information for the LED4 (Permanent) 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