High
Neon 3 lit (NO) on Saunier Duval Xeon 30ff

Your boiler is failing to detect that it is safe to ignite, meaning it has shut down to protect your home and will not provide heating or hot water until repaired.

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

Isolate electrical supply, check yellow cable between printed circuit board and air pressure switch. 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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Related fault codes

Neon 1View →Neon 2View →

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