Possible causes: The thermostat is not correctly installed. Remove the valve from the thermostat, withdraw the battery and wait for 30 sec, then put the battery back, and reinstall the thermostat, and carry out valve calibration when the device's screen displays the [F11] installation interface (you can press the key three times successively to carry out valve calibration, or do the same with the Aqara Home app). Valve failure. After replacing the malfunctioning valve, reinstall the valve and carry out valve calibration according to the above step.