I live in a building with common hot water pipes for radiators. My heating units have a thermostat that appears to be connected to a motorized valve (this one: http://www.sinro.cn/en/cp_view.asp?id=882).

I would expect that when I turn off the unit, or the temperature exceeds that which is set on the thermostat, the valve would shut and prevent more hot water from flowing through the radiator. This is not the case. Unless I close the manual shutoff valve, there is always hot water flowing through.

Does anybody know if the electronic valve might be malfunctioning, or am I making the wrong assumption?