What is the warm water valve of a car? Thermostat?

The heater water valve of an automobile is a switch, which is opened to communicate with the engine in winter and closed in summer to prevent the coolant in the engine from entering the heater water tank and avoid the temperature rise in the cab. An element of the thermostat that controls the water temperature of the engine. Generally, the engine water temperature is turned off below 87, and turned on above 87 (the coolant in the engine enters the radiator water tank, which means there is a big circulation. )