Doing The Thermistor Shuffle

You may have been advised to “move your thermistor probe” to help adjust the temperature inside the food compartment of your refrigerator.  If so, you may have also wondered “What is a thermistor?” and “Why does moving it to a different area make a difference?”.  Wonder no more fore here is the answer.

A Thermistor is a simple resistance based thermal probe that changes resistance based on the ambient air temperature.  The control board it is plugged into will read that resistance and turn on, or off, the heat source as needed to maintain a constant temperature.  As these probes begin to deteriorate the resistance may slowly become out of the range it should be in.  Therefore the control board will sense it incorrectly. This may make your refrigerator run too cold or too warm depending on how the probe deterioration occurs. By moving the thermistor from one part of the cooling fins to another you are effectively readjusting the resistance and “tricking” the control board.  For instance, if your refrigerator is running around the 42 degree mark consistently you can move the thermistor to a location that gets cold more slowly so that the food cabinet actually drops to 38 before the control board shuts of the heat source.

The picture below will help you when determining the location you need to move the thermistor too.  The most variance you will see with this method is about five degrees Fahrenheit and that’s pretty rare.  Two or three degrees Farenheit is typical so you probably shouldn’t expect any miracle fix here, but it could make that gallon of milk last a few days longer.

As you can see by the color coded box, the further you move the thermistor to the top right corner the warmer the refrigerator will become.

The further left and down you move it the colder it will become.

cooling-fins-5

Click to enlarge.