BoilerFaultCodesBiasi A short pulse every 4 seconds Fault Code
Also written as ASHORTPULSEEVERY4SECONDS — same fault.
The Biasi A short pulse every 4 seconds fault code means: your boiler is working correctly and is simply in standby mode while its built-in protection prevents the internal pipes from freezing.. It appears on 4 Biasi models in our database.
Technical description: Boiler in stand-by condition. Anti-freeze system active.
DIY fix possible
No action is required as this is a normal status message.Ensure your gas and electricity supplies are left on during cold weather.The light will stop pulsing once the boiler temperature rises or you turn on your heating.
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Biasi models that show the A short pulse every 4 seconds fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Biasi A short pulse every 4 seconds fault code information on this page is sourced and cross-checked against the official Biasi service / installation manuals for each affected model.
- Biasi Garda M90f manual (PDF)
- Biasi Riva Advance M96.24SM manual (PDF)
- Biasi Riva Compact 24S (M90E.24S) manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026