How much does it cost to fix Atag error code Error 04?

Typical repair cost for the Atag Error 04 fault is £250-500 including labour.

Error 04 High

Atag Error 04 Fault Code

Q: What does the Atag Error 04 fault code mean?

Your boiler has detected an internal fault that is preventing it from operating, which usually indicates an issue with the electrical system or the main circuit board.

Also written as ERROR04 — same fault.

The Atag Error 04 fault code means: your boiler has detected an internal fault that is preventing it from operating, which usually indicates an issue with the electrical system or the main circuit board.. It appears on 8 Atag models in our database.

Technical description: the control unit has detected an error

Typical repair cost £250-500 (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 Error 04 fault code

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

Source

Atag Error 04 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