How much does it cost to fix Ferroli error code ER 4?

Typical repair cost for the Ferroli ER 4 fault is £200-450 including labour.

ER 4 Emergency

Ferroli ER 4 Fault Code

Q: What does the Ferroli ER 4 fault code mean?

Your boiler is failing to shut off its flame properly because of a potential issue with the internal gas controls; you should turn off the gas supply at the meter immediately for your safety.

Also written as ER4 — same fault.

The Ferroli ER 4 fault code means: your boiler is failing to shut off its flame properly because of a potential issue with the internal gas controls; you should turn off the gas supply at the meter immediately for your safety.. It appears on 1 Ferroli model in our database.

Technical description: FLAME NOT EXTINGUISHED - Leaks from the gas valve

Typical repair cost £200-450 (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 ER 4 fault code

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

Xignal Repair: £200-450

Source

Ferroli ER 4 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