A short pulse every 4 seconds Low

Boiler Fault Code A short pulse every 4 seconds

Also written as ASHORTPULSEEVERY4SECONDS — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code A short pulse every 4 seconds appears across 2 boiler brands and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is currently on standby and is running its built-in protection mode to prevent the internal pipes from freezing during cold weather. (As reported on Ideal Mini)

Pick your boiler brand for the A short pulse every 4 seconds fix

Biasi A short pulse every 4 seconds 4 models Ideal A short pulse every 4 seconds 1 model

Source

Information for the A short pulse every 4 seconds 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