Thermostat, coolant - 819705 VALEO

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. ASTRA H Estate (A04)
2. ZAFIRA B Box Body/MPV (A05)
3. ASTRA Mk IV (G) Convertible (T98)
4. ASTRA Mk IV (G) Coupe (T98)
5. ASTRA Mk IV (G) Estate (T98)
6. ZAFIRA Mk I (A) (T98)
7. ASTRA G Hatchback (T98)
8. ASTRA G Saloon (T98)
9. ASTRA G Estate (T98)
10. ASTRA G Convertible (T98)
11. ASTRA H (A04)
12. ASTRA Mk V (H) (A04)
13. ASTRA H GTC (A04)
14. ASTRA G Coupe (T98)
15. ZAFIRA / ZAFIRA FAMILY B (A05)
16. 159 (939_)
17. 159 Saloon (939_)
18. ASTRA H TwinTop (A04)
19. ASTRA Mk V (H) Estate (A04)
20. BRERA (939_)
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.