How much does it cost to fix Baxi error code neon flashing (Section J)?

Typical repair cost for the Baxi neon flashing (Section J) fault is £120-250 including labour.

neon flashing (Section J) High

Baxi neon flashing (Section J) Fault Code

Q: What does the Baxi neon flashing (Section J) fault code mean?

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.

Also written as NEONFLASHINGSECTIONJ — same fault.

The Baxi neon flashing (Section J) fault code means: your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.. It appears on 2 Baxi models in our database.

Technical description: Overheat thermostat operated or 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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Baxi models that show the neon flashing (Section J) fault code

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

Source

Baxi neon flashing (Section J) 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