How To Test Refrigerator Defrost Thermostat?

If you want to be handy and do things yourself, this article is for you. The defrost thermostat supplies power flow to the heating element in the fridges and ensures that the fridge stays efficient and doesn’t defrost when it doesn’t need to. So how to check this part and make sure it’s working properly?

How do I know if my defrost thermostat is bad?

Don’t worry, it’s quite easy. All you need is a multimeter and compressed air that is usually used for keyboard cleaning. First remove the thermostat from the fridge, it’s usually located right on coils and looks like a round-shaped cylinder with two wires entering it.

At room temperature, the thermostat should not have any continuity. If there is then the thermostat is faulty but if not we still have to do another step to make sure it also activates when it gets cold enough.

Take your compressed air spray can and flip it so the nozzle where air is supposed to come out looks down while the bottom of the sprayer is up. When you spray it under pressure, the compressed air will come out super cold, so you can freeze your thermostat and make sure it’s in excellent working condition.

Remember, some thermostats only activate continuity at the temperature of -30 to -45, and it might take a couple of tries. Usually, as soon as the thermostat is covered with ice, it should pass the continuity through its wires and be able to provide power to the heating element. If the thermostat passes this test, be sure that it’s working correctly.

Author: Jacob Dillard

My name is Jacob Dillard, and I am the author of articles at Appliance Repair Expert. Since childhood, I have been fascinated by technology and spent much time reading different books and trying to repair my first CD player. Then, I graduated from the University of Toronto with a degree in Applied Science and Engineering. In a year, I got my first job as a technician at an appliance repair company. After years of practice and working with professionals, I decided it was time to share my knowledge and experience here at Appliance Repair Expert. I want to help you understand everything related to appliance repair, maintenance and installation in the simplest way possible. It will be fun, believe me!