Medium
F35 on Ferroli iBoiler 24

Your boiler has detected an issue with the quality or consistency of the incoming electricity supply from the power grid.

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

Faulty mains frequency – electric mains error

Engineer required

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

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Related fault codes

F34View →A06View →

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