Medium
F8 on Saunier Duval Isofast

Your boiler is having trouble reading the temperature inside its hot water storage tank, which means it may struggle to provide a consistent supply of hot water.

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

Micro-accumulator sensor fault

Engineer required

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

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Related fault codes

F7View →F20View →

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