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Neon B Flashing very slowly (every 5 seconds) on Alpha CD28

Your boiler is receiving power normally and is currently in standby mode waiting for a heating or hot water demand.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Electricity supply to the boiler is on.

From this model's manual
Verified against the Alpha/Alpha Alpha Cb24 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

No action is required as this is a normal operational status light indicating the boiler is powered on.

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A cover plan would handle faults like Neon B Flashing very slowly (every 5 seconds): no call-out fees, no surprise bills.

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All 8 fault codes on the CD28

Seeing a different code? Every code this model can display, in one place.

Neon A and B Flashing on and off alternativelyNeon A and B Flashing on and off at the same timeNeon A Flashing on and offNeon A Illuminated continuouslyNeon B Flashing (every 5 seconds)Neon B Flashing on and offNeon B Illuminated continuously

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