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. TOURAN (1T1, 1T2)
2. A3 (8P1)
3. A3 / S3 (8P1)
4. GOLF V (1K1)
5. RABBIT V (1K1)
6. OCTAVIA II (1Z3)
7. LAURA II (1Z3)
8. A3 Sportback (8PA)
9. OCTAVIA II Combi (1Z5)
10. GOLF PLUS (5M1, 521)
11. PASSAT (3C2)
12. PASSAT Saloon (3C2)
13. PASSAT / Magotan (3C2)
14. JETTA III (1K2)
15. JETTA I Saloon (1K2)
16. JETTA V (1K2)
17. BORA V (1K2)
18. VENTO III (1K2)
19. PASSAT Variant (3C5)
20. PASSAT Estate (3C5)
21. See more in applications

The principle of the thermostat work

The classic VEMO 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.