High
F9 on Saunier Duval Semia Condens F30 E

Your boiler is struggling to detect the water level inside the system because the sensor that monitors it is disconnected or experiencing a communication error.

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

Water pressure sensor fault. Faulty sensor connection. Check wiring

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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