How much does it cost to fix boiler error code LOW POWER SUPPLY FROM MAINS?

Typical repair cost for the boiler LOW POWER SUPPLY FROM MAINS fault is £120-250 including labour.

LOW POWER SUPPLY FROM MAINS High

Boiler Fault Code LOW POWER SUPPLY FROM MAINS

Also written as LOWPOWERSUPPLYFROMMAINS — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code LOW POWER SUPPLY FROM MAINS appears across 1 boiler brand and 2 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 the electricity coming from your home's wall socket is unstable and outside the safe voltage range it needs to operate correctly. (As reported on Johnson Starley Quantec C)

Pick your boiler brand for the LOW POWER SUPPLY FROM MAINS fix

Johnson Starley LOW POWER SUPPLY FROM MAINS 2 models

Source

Information for the LOW POWER SUPPLY FROM MAINS 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