BoilerFaultCodes Neon A flashing High
Boiler Fault Code Neon A flashing
Also written as NEONAFLASHING — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Neon A flashing appears across 1 boiler brand and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's internal thermometer is providing confusing information, so it has turned itself off as a precaution to prevent overheating. (As reported on Alpha CD24)
Pick your boiler brand for the Neon A flashing fix
Source
Information for the Neon A flashing fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026