LED 4 (Permanent light) Low

Ferroli LED 4 (Permanent light) Fault Code

Also written as LED4PERMANENTLIGHT — same fault.

The Ferroli LED 4 (Permanent light) fault code means: your boiler is simply indicating that the central heating system is currently active and running normally to warm your radiators.. It appears on 5 Ferroli models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Central heating circuit on

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 LED 4 (Permanent light) fault code

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

Source

Ferroli LED 4 (Permanent light) 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