Performing work on the cooling system can be laborious; however, auto technicians must ensure the entire repair or replacement is completed fully. After replacing a thermostat, the technician should ensure all air pockets are removed from the cooling system. Otherwise, the vehicle will be more likely to overheat.

After replacing the thermostat, refill the antifreeze. Leave the radiator cap off, and start the vehicle. Wait five minutes to allow all of the antifreeze to circulate throughout the engine. Turn off the engine, and allow the engine to cool. Recheck the antifreeze level, and top it off if necessary.