How much does it cost to fix Ferroli error code F11 – A11?

Typical repair cost for the Ferroli F11 – A11 fault is £90-160 including labour.

F11 – A11 High

Ferroli F11 – A11 Fault Code

Q: What does the Ferroli F11 – A11 fault code mean?

Your boiler has detected an issue with the sensor that monitors the temperature of the water coming back into the system, causing the boiler to stop working for safety.

Also written as F11A11 — same fault.

The Ferroli F11 – A11 fault code means: your boiler has detected an issue with the sensor that monitors the temperature of the water coming back into the system, causing the boiler to stop working for safety.. It appears on 3 Ferroli models in our database.

Technical description: Return sensor fault

Typical repair cost £90-160 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Ferroli models that show the F11 – A11 fault code

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

Source

Ferroli F11 – A11 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