High
75 / 76 on Alpha FMK

Your boiler is struggling to accurately measure its own temperature, meaning it cannot safely or effectively heat your water.

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

Return/flow sensor fault from possible failure of one or both sensors

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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