10 High

Unical 10 Fault Code

The Unical 10 fault code means: your boiler has shut down because it has detected it is getting too hot, likely due to a lack of water flow through the system.. It appears on 2 Unical models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: HIGH TEMPERATURE - Boiler temperature too high
Typical repair cost £100-350 (including labour)

DIY fix possible

Check that your radiators are turned on and the valves are openEnsure your system water pressure is between 1.0 and 1.5 barPress the 'Reset' button on the control panel to see if the fault clears

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Unical models that show the 10 fault code

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

Source

Unical 10 fault code information on this page is sourced and cross-checked against the official Unical service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026