Flue gas pressure switch High

Biasi Flue gas pressure switch Fault Code

Also written as FLUEGASPRESSURESWITCH — same fault.

The Biasi Flue gas pressure switch fault code means: your boiler has detected a problem with how it safely vents exhaust fumes, which is preventing it from lighting to ensure your safety.. It appears on 1 Biasi model in our database.

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.

Technical description: Can temporarily stop the ignition of the burner but allow its ignition when the cause of the intervention has stopped.
Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Biasi models that show the Flue gas pressure switch fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Biasi Flue gas pressure switch fault code information on this page is sourced and cross-checked against the official Biasi service / installation manuals for each affected model.

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