Boiler Fault Code Pulse Red (6 flashes)

Also written as PULSERED6FLASHES — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code Pulse Red (6 flashes) appears across 1 boiler brand and 2 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 detect the airflow needed for safe operation, so it has shut down to prevent it from firing up improperly. (As reported on Potterton Envoy Plus)