What is a thermostat?
A thermostat is a controller that reacts to a set temperature (temperature controller). Depending on the setting and measured temperature, it influences the flow of a fluid - for example, for cooling an engine, in a refrigerator, a fixture in the kitchen or bathroom, or on a radiator.
How does a radiator thermostat work?
The temperature controller of a heater reacts to the existing room temperature. The set temperature is adjusted at the thermostat head.
If it is warmer in the room than the temperature set at the thermostatic head, a pin at the bottom of the valve is pressed in and the opening of the valve is restricted or closed. Thus, less or no heating water flows into the radiator.
If it is colder in the room than the temperature set on the thermostatic head, the valve is opened. This allows more heating water to flow through the radiator until the set temperature is reached. Then the valve automatically closes a little to maintain the set temperature in the room.