Boiler Fault Code Red neon (A) flashing

Also written as REDNEONAFLASHING — same fault.

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

Fault code Red neon (A) flashing appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has become too hot and has automatically turned itself off as a safety precaution to prevent damage. (As reported on Alpha HETEC)