How much does it cost to fix boiler error code Mains light?

Typical repair cost for the boiler Mains light fault is £0-60 including labour.

Mains light Low

Boiler Fault Code Mains light

Also written as MAINSLIGHT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code Mains light 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 This light simply shows that your boiler is receiving electrical power and is switched on. (As reported on Potterton Puma 100e)

Pick your boiler brand for the Mains light fix

Potterton Mains light 1 model

Source

Information for the Mains light 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 7 July 2026