neon flashing (Section J) High

Boiler Fault Code neon flashing (Section J)

Also written as NEONFLASHINGSECTIONJ — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code neon flashing (Section J) appears across 2 boiler brands and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has switched itself off because it has detected an unsafe build-up of heat in either the water system or the exhaust flue. (As reported on Potterton Performa 24 Eco HE)

Pick your boiler brand for the neon flashing (Section J) fix

Baxi neon flashing (Section J) 2 models Potterton neon flashing (Section J) 2 models

Source

Information for the neon flashing (Section J) 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