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. JETTA IV (162, 163, AV3, AV2)
2. JETTA VI (162, 163, AV3, AV2)
3. JETTA / CLASICO VI (162, 163, AV3, AV2)
4. BORA IV (162, 163, AV3, AV2)
5. A3 (8P1)
6. A3 / S3 (8P1)
7. A3 Sportback (8PA)
8. GOLF PLUS (5M1, 521)
9. PASSAT Variant (3C5)
10. PASSAT Estate (3C5)
11. LEON (1P1)
12. ALTEA (5P1)
13. PASSAT (3C2)
14. PASSAT Saloon (3C2)
15. PASSAT / Magotan (3C2)
16. JETTA III (1K2)
17. JETTA I Saloon (1K2)
18. JETTA V (1K2)
19. BORA V (1K2)
20. VENTO III (1K2)
21. See more in applications

The principle of the thermostat work

The classic FEBI BILSTEIN 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.