straight physics tells you that hot stuff rises and cold stuff drops
the hot water goes into the top of the radiator and cools and drops to the bottom of the radiator where it comes out and goes in through the bottom of the thermostat - you have the flow backwards.
the hot water goes into the top of the radiator and cools and drops to the bottom of the radiator where it comes out and goes in through the bottom of the thermostat - you have the flow backwards.