How much does it cost to fix Ferroli error code F4?

Typical repair cost for the Ferroli F4 fault is £120-250 including labour.

F4 High

Ferroli F4 Fault Code

Q: What does the Ferroli F4 fault code mean?

Your boiler has detected an issue with its internal ventilation, meaning it cannot safely remove combustion gases, so it has shut down to prevent potential danger.

The Ferroli F4 fault code means: your boiler has detected an issue with its internal ventilation, meaning it cannot safely remove combustion gases, so it has shut down to prevent potential danger.. It appears on 5 Ferroli models in our database.

Technical description: The air pressure switch is not making contact (contacts open). Check the fan, the venturi, the pressure switch and the flue.

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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Ferroli models that show the F4 fault code

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

Source

Ferroli F4 fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.

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