How much does it cost to fix boiler error code B Illuminated continuously?

Typical repair cost for the boiler B Illuminated continuously fault is £120-250 including labour.

B Illuminated continuously High

Boiler Fault Code B Illuminated continuously

Also written as BILLUMINATEDCONTINUOUSLY — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code B Illuminated continuously 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 has stopped working because it failed to light the internal flame, resulting in no heating or hot water until it is successfully restarted. (As reported on Alpha Cd25)

Pick your boiler brand for the B Illuminated continuously fix

Alpha B Illuminated continuously 5 models

Source

Information for the B 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