High
F31 on Ferroli Optimax

Your boiler has lost signal from the temperature sensor that monitors the hot water leaving the unit, meaning it cannot safely regulate how much it heats your home.

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

Delivery sensor fault

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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Related fault codes

F30View →

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