Neon D High

Alpha Neon D Fault Code

Also written as NEOND — same fault.

The Alpha Neon D fault code means: your boiler has lost power or has an internal electrical fault, meaning it cannot provide any heating or hot water until an electrical issue is resolved.. It appears on 3 Alpha models in our database.

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: Neon D illuminated continuously - check electrical supply, main terminal fuse, or PCB
Typical repair cost £120-£350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Alpha models that show the Neon D fault code

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

Source

Alpha Neon D 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