BoilerFaultCodesSaunier Duval Neon 2 Fault Code
Also written as NEON2 — same fault.
The Saunier Duval Neon 2 fault code means: your boiler has stopped working because a safety switch has detected that the unit became too hot and triggered a shutdown.. It appears on 2 Saunier Duval models in our database.
Technical description: 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.
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 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Saunier Duval Neon 2 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 7 July 2026