BoilerFaultCodes A Illuminated continuously High
Boiler Fault Code A Illuminated continuously
Also written as AILLUMINATEDCONTINUOUSLY — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code A Illuminated continuously appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has attempted to start but is unable to ignite its internal flame, meaning your heating and hot water will not work. (As reported on Alpha C27)
Pick your boiler brand for the A Illuminated continuously fix
Source
Information for the A Illuminated continuously 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