How much does it cost to fix boiler error code Lights On Flash Flash?

Typical repair cost for the boiler Lights On Flash Flash fault is £150-300 including labour.

Lights On Flash Flash High

Boiler Fault Code Lights On Flash Flash

Also written as LIGHTSONFLASHFLASH — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code Lights On Flash Flash appears across 2 boiler brands and 6 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 water is not circulating properly through the system, so it has shut down to protect the internal components from overheating. (As reported on Potterton Promax 15/2 HE Plus)

Pick your boiler brand for the Lights On Flash Flash fix

Baxi Lights On Flash Flash 3 models Potterton Lights On Flash Flash 3 models

Source

Information for the Lights On Flash Flash 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 7 July 2026