Halstead NEON 3 Fault Code
Also written as NEON3 — same fault.
The Halstead NEON 3 fault code means: your boiler is struggling because the internal fan is stuck running without the system actually igniting to produce heat.. It appears on 1 Halstead model in our database.
Technical description: FAN RUNNING
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Halstead models that show the NEON 3 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Halstead NEON 3 fault code information on this page is sourced and cross-checked against the official Halstead service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026