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

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

B Illuminated continuously High

Alpha B Illuminated continuously Fault Code

Q: What does the Alpha B Illuminated continuously fault code mean?

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.

Also written as BILLUMINATEDCONTINUOUSLY — same fault.

The Alpha B Illuminated continuously fault code means: 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.. It appears on 5 Alpha models in our database.

Technical description: Burner has failed to light. Rotate selector switch to the reset position (3) and the ignition sequence will restart after a delay of about 30 seconds.

Typical repair cost £120-250 (including labour)

DIY fix possible

Turn the selector dial on the front of the unit to the 'Reset' position.Wait for 30 seconds for the boiler to click and attempt the ignition sequence again.If the boiler fails to ignite repeatedly, check that your gas supply is turned on and your gas meter has credit.

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Alpha models that show the B Illuminated continuously fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Alpha B Illuminated continuously fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

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