Potterton neon flashing (Section D) Fault Code
Also written as NEONFLASHINGSECTIOND — same fault.
The Potterton neon flashing (Section D) fault code means: your boiler has detected that the internal fan responsible for safely removing exhaust gases is struggling to spin at the right speed, so it has shut down to keep your home safe.. It appears on 1 Potterton model in our database.
Technical description: Fan fault - Fan not running at maximum speed
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Potterton models that show the neon flashing (Section D) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton neon flashing (Section D) fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026