Thermostat is a device for maintaining a static (constant) temperature, as its name implies. There are thermostats of different designs in many devices and mechanisms, from water heaters to refrigerators. There is also a thermostat in a car's internal combustion engine (liquid-cooled, of course). In a car, the thermostat regulates the temperature of the coolant (antifreeze): it accelerates the warm-up of a cold engine and provides heat removal from the hot one. Therefore, the engine works more efficiently and more comfortably for the driver, especially in winter - without a thermostat, the stove would usually blew cold air.

1. G-CLASS (W461)
2. SPRINTER 3,5-t Bus (906)
3. SPRINTER 3,5-t Van (906)
4. E-CLASS (W212)
5. E-CLASS Saloon (W212)
6. SPRINTER 3,5-t Platform/Chassis (906)
7. M-CLASS (W164)
8. M-CLASS SUV (W164)
9. E-CLASS (W211)
10. E-CLASS Saloon (W211)
11. E-CLASS T-Model (S211)
12. CLK (C209)
13. C-CLASS (W203)
14. C-CLASS Saloon (W203)
15. CLS (C219)
16. R-CLASS (W251, V251)
17. C-CLASS T-Model (S203)
18. GL-CLASS (X164)
19. GL-CLASS SUV (X164)
20. SPRINTER 3-t Van (906)
21. See more in applications

The principle of the thermostat work

The classic VALEO brand Thermostat, coolant is a movable valve that moves due to a change in the external environment - heating or cooling of antifreeze. The thermostat is made of a thermoelement filled with a substance resembling wax in structure - ceresin, with the addition of copper powder, graphite or aluminum for better thermal conductivity. At a certain temperature of the antifreeze, ceresin expands, opening the thermostat valve. When the motor cools down, ceresin contracts and the thermostat closes again.