Flashing High

Boiler Fault Code Flashing

Also written as FLASHING — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Flashing 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 is failing to monitor the temperature of the water circulating through your heating system, which has caused it to shut down for safety. (As reported on Heatline Capriz 25S 28S)

Pick your boiler brand for the Flashing fix

Heatline Flashing 1 model Potterton Flashing 3 models

Source

Information for the Flashing 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