High
neon illuminated on Alpha CD28

Your boiler's electronic control panel is experiencing an internal fault, causing a warning light to stay on and likely preventing your heating or hot water from working.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

1. Replace neon PCB. 2. check PCB-M11 connector. 3. 20V DC across terminals 49, 52. 4. Replace main PCB.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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