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. BX (XB-_)
2. 405 I (15B)
3. 405 I Saloon (15B)
4. 405 � (15B)
5. TIPO (160_)
6. REGATA (138_)
7. REGATA Saloon (138_)
8. PRISMA (831_)
9. DELTA I (831_)
10. DELTA � (831_)
11. DEDRA (835_)
12. DELTA II (836_)
13. DELTA Mk II (836_)
14. TEMPRA (159_)
15. TEMPRA S.W. (159_)
16. TEMPRA SW (159_)
17. DEDRA SW (835_)
18. 309 II (3C, 3A)
19. 309 Mk II (3C, 3A)
20. 405 I Break (15E)
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.