How much does it cost to fix Saunier Duval error code Neon 2 NOT lit?

Typical repair cost for the Saunier Duval Neon 2 NOT lit fault is £120-250 including labour.

Neon 2 NOT lit High

Saunier Duval Neon 2 NOT lit Fault Code

Q: What does the Saunier Duval Neon 2 NOT lit fault code mean?

Your boiler has automatically shut itself down because it detected that it is getting too hot, likely due to a flow restriction or a failing safety sensor.

Also written as NEON2NOTLIT — same fault.

The Saunier Duval Neon 2 NOT lit fault code means: your boiler has automatically shut itself down because it detected that it is getting too hot, likely due to a flow restriction or a failing safety sensor.. It appears on 2 Saunier Duval models in our database.

Technical description: Overheat cut off device tripped or thermostat, overheat cut off device faulty

Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Saunier Duval models that show the Neon 2 NOT lit fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Saunier Duval Neon 2 NOT lit fault code information on this page is sourced and cross-checked against the official Saunier Duval service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026