BoilerFaultCodes neons flashing (Section D) High
Boiler Fault Code neons flashing (Section D)
Also written as NEONSFLASHINGSECTIOND — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code neons flashing (Section D) appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has detected that the internal fan responsible for safely exhausting fumes is not rotating or working correctly, so it has shut down to keep your home safe. (As reported on Potterton Performa System HE)
Pick your boiler brand for the neons flashing (Section D) fix
Source
Information for the neons flashing (Section D) fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026