F41 High

Ferroli F41 Fault Code

The Ferroli F41 fault code means: your boiler's internal computer is confused because its internal temperature sensors are either disconnected or are reading temperatures that suggest they have been installed in the wrong positions.. It appears on 5 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: Flow/return sensor orientation fault
Typical repair cost £120-220 (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 F41 fault code

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

Source

Ferroli F41 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 7 July 2026