How much does it cost to fix Atag error code Err.4?

Typical repair cost for the Atag Err.4 fault is £120-250 including labour.

Err.4 Medium

Atag Err.4 Fault Code

Q: What does the Atag Err.4 fault code mean?

Your boiler is displaying a historical record of an older issue, which means the current problem is likely linked to a fault that happened several times in the past.

Also written as ERR4 — same fault.

The Atag Err.4 fault code means: your boiler is displaying a historical record of an older issue, which means the current problem is likely linked to a fault that happened several times in the past.. It appears on 2 Atag models in our database.

Technical description: 4th last predecessing error

Typical repair cost £120-250 (including labour)

Engineer required

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

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Atag models that show the Err.4 fault code

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

Source

Atag Err.4 fault code information on this page is sourced and cross-checked against the official Atag service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026