High
356 on Worcester Bosch 30i Junior

Your boiler has detected that the electrical supply coming into your home is too weak or unstable for it to operate safely.

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.

Technical description

Low mains voltage – the voltage may be interrupted or inconsistent and needs checking

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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Related fault codes

A1View →C6View →

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