Flash 4 times per second High

Boiler Fault Code Flash 4 times per second

Also written as FLASH4TIMESPERSECOND — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Flash 4 times per second 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 has detected an internal communication or airflow issue that has caused it to shut down for safety. (As reported on Worcester Bosch 24si II)

Pick your boiler brand for the Flash 4 times per second fix

Worcester Bosch Flash 4 times per second 1 model

Source

Information for the Flash 4 times per second 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