High
FL on Biasi Advance Plus

Your boiler has detected that the water pressure in your heating system has dropped too low and needs to be topped up to function correctly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Filling request: The boiler works regularly and the display shows all the icons, but the signal FL is flashing every 1 sec

From this model's manual
Verified against the Biasi Advance Plus installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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