4 (Permanent) Medium

Ferroli 4 (Permanent) Fault Code

Also written as 4PERMANENT — same fault.

The Ferroli 4 (Permanent) fault code means: your boiler thinks the central heating should be running constantly, which can lead to overheating or your radiators staying on when they shouldn't.. It appears on 4 Ferroli models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Central heating circuit ON
Typical repair cost £120-280 (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 4 (Permanent) fault code

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

Source

Ferroli 4 (Permanent) 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