A combustion engine must operate within a certain temperature window in order to function optimally. The temperature is controlled by a coolant and a thermostat. The thermostat ensures that the engine reaches its ideal operating temperature as quickly as possible and then maintains it continuously. A defective or blocked thermostat can cause the engine to overheat. This is why febi only offers coolant thermostats in OE matching quality. Quality by Conviction: Our quality management tests the offered thermostats for different requirements and loads. These include function, accuracy of fit, dimensional accuracy, and material quality. Supplied Complete. Repaired Non-stop: In everyday workshop life, it is not uncommon for a worn part to have to be replaced as well as any fixings. However, these additional parts - usually bolts or nuts - are often not included with the individually available replacement part. febi mainly offers thermostats with housings in which the seal and the temperature sensor are already integrated.