Boiler Fault Code LOW MAINS VOLTAGE

Also written as LOWMAINSVOLTAGE — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code LOW MAINS VOLTAGE appears across 2 boiler brands and 18 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is receiving less electrical power than it needs to operate, which may be due to a loose wire, a power supply issue in your home, or a fault with the supply line to the property. (As reported on Ideal Vogue Combi)