How much does it cost to fix Baxi error code D neon flashing?

Typical repair cost for the Baxi D neon flashing fault is £100-£250 including labour.

D neon flashing High

Baxi D neon flashing Fault Code

Q: What does the Baxi D neon flashing fault code mean?

Your boiler has become too hot and has shut down as a safety precaution to prevent damage.

Also written as DNEONFLASHING — same fault.

The Baxi D neon flashing fault code means: your boiler has become too hot and has shut down as a safety precaution to prevent damage.. It appears on 1 Baxi model in our database.

Technical description: Overheat thermostat or flue thermostat tripped; investigation required in section D

Typical repair cost £100-£250 (including labour)

DIY fix possible

Turn the boiler off and allow it to cool down for 30 minutesEnsure all radiator valves are fully open to allow water to flowTurn the selector switch to the reset position for five seconds and then back to the menu

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Baxi models that show the D neon flashing fault code

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

Combi 130e Repair: £100-£250

Source

Baxi D neon flashing 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