Slow Flashing (2Hz) High

Boiler Fault Code Slow Flashing (2Hz)

Also written as SLOWFLASHING2HZ — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Slow Flashing (2Hz) appears across 1 boiler brand 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 failed to ignite and has locked itself out for safety, meaning you currently have no heating or hot water. (As reported on Glow-worm Micron 30ff)

Pick your boiler brand for the Slow Flashing (2Hz) fix

Glow-worm Slow Flashing (2Hz) 4 models

Source

Information for the Slow Flashing (2Hz) 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