F45 High

Ferroli F45 Fault Code

The Ferroli F45 fault code means: your boiler has detected an issue with the sensor that monitors the temperature of the exhaust fumes, so it has safely shut down to prevent potential overheating.. It appears on 4 Ferroli models 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: Flue gas sensor fault
Typical repair cost £150-250 (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 F45 fault code

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

Source

Ferroli F45 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