How much does it cost to fix Ariston error code B01?

Typical repair cost for the Ariston B01 fault is £120-280 including labour.

B01 High

Ariston B01 Fault Code

Q: What does the Ariston B01 fault code mean?

Your boiler has switched itself off because it has reached an unsafe temperature and needs to cool down before it can be used again.

The Ariston B01 fault code means: your boiler has switched itself off because it has reached an unsafe temperature and needs to cool down before it can be used again.. It appears on 6 Ariston models in our database.

Technical description: Over Heat Thermostat

Typical repair cost £120-280 (including labour)

DIY fix possible

Turn off the boiler and allow it to cool for 20 minutes.Ensure all radiator valves are fully open and there is no air trapped in the system.Check that the system pressure is between 1.0 and 1.5 bar on the gauge.Press the Reset button on the control panel to restart the boiler.

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Ariston models that show the B01 fault code

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

Source

Ariston B01 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

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