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. 4 (112_)
2. 4 Hatchback (112_)
3. 4 Box Body/MPV (R21_, R23_)
4. 5 (122_)
5. LE CAR (122_)
6. SUPER 5 (B/C40_)
7. 11 (B/C37_)
8. ENCORE (B/C37_)
9. 19 I (B/C53_)
10. 19 � (B/C53_)
11. 19 II Chamade (L53_)
12. 19 Mk II Chamade (L53_)
13. 19 II (B/C53_)
14. 19 Mk II (B/C53_)
15. 19 I Chamade (L53_)
16. 19 � Chamade (L53_)
17. RAPID Box Body/MPV (F40_, G40_)
18. EXPRESS Box Body/MPV (F40_, G40_)
19. EXTRA Van (F40_, G40_)
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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.