How much does it cost to fix Ferroli error code F42 – A42?

Typical repair cost for the Ferroli F42 – A42 fault is £120-240 including labour.

F42 – A42 High

Ferroli F42 – A42 Fault Code

Q: What does the Ferroli F42 – A42 fault code mean?

Your boiler has detected an inconsistent temperature reading between its internal sensors and has shut down to prevent overheating.

Also written as F42A42 — same fault.

The Ferroli F42 – A42 fault code means: your boiler has detected an inconsistent temperature reading between its internal sensors and has shut down to prevent overheating.. It appears on 3 Ferroli models in our database.

Technical description: Sensor control protection activation

Typical repair cost £120-240 (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 F42 – A42 fault code

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

Source

Ferroli F42 – A42 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