Medium
F7 on Keston Celsius 30

Your boiler has detected that the electricity supply coming into your home is at a lower voltage than it needs to operate safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Low mains voltage

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F1View →F3View →

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