High
Neon 4 lit on Saunier Duval Xeon 30ff

Your boiler's control system is failing to send the necessary electrical signal to the gas valve, meaning the boiler cannot ignite 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

Is Neon 4 lit? NO: Is there 230V~ between pilot multi-functional control solenoid blue and brown connections? NO: Isolate supply, test harness continuity. If satisfactory replace printed circuit board.

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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