High
F42 on Ferroli Arean

Your boiler is currently unable to detect the flow of water because one of its internal sensors has failed, meaning it will not switch on to provide heating or hot 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

Flow sensor fault (Sensor damaged)

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

F43View →F47View →

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