Boiler Fault Code MAINS LED FLASHING

Also written as MAINSLEDFLASHING — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code MAINS LED FLASHING appears across 2 boiler brands and 3 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 it is running too hot or has experienced an internal control error, so it has safely shut itself down to prevent damage. (As reported on Potterton Performa System HE)