Emergency
Neon 2 on Saunier Duval Xeon 40ff

Your boiler has automatically shut down because it has detected dangerously high internal temperatures.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Overheat cut off device tripped or thermostat, overheat cut off device faulty

From this model's manual
Verified against the Saunier Duval/Saunier Duval G101 Saunier Duval Xeon 40ff 4192040 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 emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 4 fault codes on the Xeon 40ff

Seeing a different code? Every code this model can display, in one place.

Neon 1Neon 3Neon 4

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