High
F10 on Ferroli Optimax

Your boiler has lost its ability to monitor the temperature of the water leaving the unit, usually due to a faulty sensor or a wiring issue, causing the system to shut down for safety.

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

Flow sensor fault (Sensor damaged or short circuited / Sensor damaged or wiring broken)

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

F11View →F14View →A03View →

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