How much does it cost to fix boiler error code neon flashing (3rd instance)?

Typical repair cost for the boiler neon flashing (3rd instance) fault is £150-300 including labour.

neon flashing (3rd instance) High

Boiler Fault Code neon flashing (3rd instance)

Also written as NEONFLASHING3RDINSTANCE — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code neon flashing (3rd instance) appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is struggling to confirm it is venting exhaust gases safely, causing the internal fan to run continuously at high speed to try and clear the system. (As reported on Potterton Performa 28i)

Pick your boiler brand for the neon flashing (3rd instance) fix

Potterton neon flashing (3rd instance) 1 model

Source

Information for the neon flashing (3rd instance) 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