High
LOW POWER SUPPLY FROM MAINS on Johnson Starley Quantec C

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.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Mains supply voltage outside of 190V - 256V range

From this model's manual
Verified against the Johnson Starley Quantec C installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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