F6 High

Ferroli F6 Fault Code

The Ferroli F6 fault code means: your boiler has lost its ability to measure the temperature of the water heading to your radiators, meaning your heating system will likely stop working for safety.. It appears on 2 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: Central heating flow temperature sensor fault (open circuit or short circuit). Check the sensor and its wiring.
Typical repair cost £90-£160 (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 F6 fault code

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

Source

Ferroli F6 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