How much does it cost to fix Atag error code 101?

Typical repair cost for the Atag 101 fault is £150-450 including labour.

101 High

Atag 101 Fault Code

Q: What does the Atag 101 fault code mean?

Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.

The Atag 101 fault code means: your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.. It appears on 18 Atag models in our database.

Technical description: Overheat

Typical repair cost £150-450 (including labour)

DIY fix possible

Check that your radiator valves are open to allow water to flow.Ensure the system pressure is between 1.0 and 1.5 bar on the pressure gauge.Press the Reset button on the control panel to see if the fault clears.

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Atag models that show the 101 fault code

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

Source

Atag 101 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 31 August 2026