How much does it cost to fix Atag error code Err.1?

Typical repair cost for the Atag Err.1 fault is £150-300 including labour.

Err.1 High

Atag Err.1 Fault Code

Q: What does the Atag Err.1 fault code mean?

Your boiler has detected an internal logic error and has locked itself out to prevent potential damage, meaning you currently have no heating or hot water.

Also written as ERR1 — same fault.

The Atag Err.1 fault code means: your boiler has detected an internal logic error and has locked itself out to prevent potential damage, meaning you currently have no heating or hot water.. It appears on 2 Atag models in our database.

Technical description: Predecessing error 1

Typical repair cost £150-300 (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.1 fault code

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

E22c Repair: £150-300
Q 25S

Source

Atag Err.1 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