How much does it cost to fix Saunier Duval error code Neon 4 NOT lit?

Typical repair cost for the Saunier Duval Neon 4 NOT lit fault is £150-350 including labour.

Neon 4 NOT lit High

Saunier Duval Neon 4 NOT lit Fault Code

Q: What does the Saunier Duval Neon 4 NOT lit fault code mean?

Your boiler is failing to light the burner, meaning it cannot produce heat or hot water because it has detected an issue with the ignition process.

Also written as NEON4NOTLIT — same fault.

The Saunier Duval Neon 4 NOT lit fault code means: your boiler is failing to light the burner, meaning it cannot produce heat or hot water because it has detected an issue with the ignition process.. It appears on 2 Saunier Duval models in our database.

Technical description: Ignition, pilot or flame proving fault

Typical repair cost £150-350 (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 4 NOT lit fault code

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

Source

Saunier Duval Neon 4 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