How much does it cost to fix Alpha error code Neon B flashing?

Typical repair cost for the Alpha Neon B flashing fault is £120-250 including labour.

Neon B flashing High

Alpha Neon B flashing Fault Code

Q: What does the Alpha Neon B flashing fault code mean?

Your boiler has automatically shut itself down because it detected that it is running too hot, possibly due to trapped air or a blockage in the system.

Also written as NEONBFLASHING — same fault.

The Alpha Neon B flashing fault code means: your boiler has automatically shut itself down because it detected that it is running too hot, possibly due to trapped air or a blockage in the system.. It appears on 6 Alpha models in our database.

Technical description: Overheat thermostat or thermal fuse has operated

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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Alpha models that show the Neon B flashing fault code

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

Source

Alpha Neon B flashing fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026