BoilerFaultCodes Neon B Flashing very slowly Low
Boiler Fault Code Neon B Flashing very slowly
Also written as NEONBFLASHINGVERYSLOWLY — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Neon B Flashing very slowly appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is currently stuck in a standby or waiting mode because it is receiving power but has not been triggered to start heating. (As reported on Alpha C27)
Pick your boiler brand for the Neon B Flashing very slowly fix
Source
Information for the Neon B Flashing very slowly 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