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. A3 (8P1)
2. A3 / S3 (8P1)
3. TOURAN (1T1, 1T2)
4. GOLF V (1K1)
5. RABBIT V (1K1)
6. A6 (4F2, C6)
7. A6 Saloon (4F2, C6)
8. A6 / S6 (4F2, C6)
9. ALTEA (5P1)
10. OCTAVIA II (1Z3)
11. LAURA II (1Z3)
12. A3 Sportback (8PA)
13. OCTAVIA II Combi (1Z5)
14. A4 (8EC, B7)
15. A4 Saloon (8EC, B7)
16. A4 / S4 (8EC, B7)
17. TOLEDO III (5P2)
18. GOLF PLUS (5M1, 521)
19. A4 Avant (8ED, B7)
20. A4 / S4 Avant (8ED, B7)
21. See more in applications

The principle of the thermostat work

The classic MEYLE 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.