High
Neon 2 lit on Saunier Duval Xeon 30ff

Your boiler has stopped working because a safety sensor has tripped, likely due to the system getting too hot.

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.

What the manual says

Manufacturer manual

Is neon 2 lit? NO: For gravity domestic hot water systems only, check continuity of yellow link. For fully pumped systems, check overheat reset. If satisfactory replace overheat device.

From this model's manual
Verified against the Saunier Duval Xeon 30ff installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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 3View →

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