If something goes awry in your engine, then it's possible your thermostat can get stuck in the open position. This could be caused by some kind of build-up of debris, grease, dirt, or some kind of corrosion that prevents it from closing properly.

Is it bad if my thermostat is stuck open?

A stuck-open thermostat can also cause lack of heat from the heating system. The Check Engine light may come on too. Thermostat stuck closed: When the thermostat is stuck closed, the engine might overheat. Besides these two cases, the thermostat may also need to be replaced if the thermostat housing is leaking coolant.

How much does it cost to fix a stuck open thermostat?

It plays a very important part in the regulation of temperature in your vehicle so when something has gone wrong with your thermostat you definitely need to get it repaired as soon as you possibly can. The cost of getting a thermostat replaced in a car is about $200 to $300 on average.