Wax thermostatic element
![Car engine wax thermostatic element](/Images/godic/202502/20/Carthermostat5739.jpg")
![Double valve engine thermostat](/Images/godic/202502/20/Double_valve_automotive_thermostat5739.jpg")
The wax thermostatic element was invented in 1936 by Sergius Vernet (1899-1968). Its principal application is in automotive thermostats used in the engine cooling system. The first applications in the plumbing and heating industries were in Sweden (1970) and in Switzerland (1971).