High
0A17 on Alpha FMK

Your boiler is struggling to heat the water properly because it thinks it is taking too long for the temperature to rise once the burner starts.

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 sensor temperature rise incorrect (time taken for flow temperature to rise is too long.

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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