Medium
F35 on Ferroli Optima 201

Your boiler is struggling because the electricity supply coming into your home is not stable or consistent enough for it to operate.

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

Irregular mains frequency

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 →F37View →

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