Baxi neon flashing (Section I) Fault Code
Also written as NEONFLASHINGSECTIONI — same fault.
The Baxi neon flashing (Section I) fault code means: your boiler is lighting up but shutting off shortly after because it cannot confirm that the flame is staying on, meaning you currently have no heating or hot water.. It appears on 2 Baxi models in our database.
Technical description: Burner extinguishes after 10 seconds - flame sensing fault
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Baxi models that show the neon flashing (Section I) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi neon flashing (Section I) fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026