Tag - test thermistor

**NOTICE**
Due the danger and complexity of electronic equipment repair, the following technical tip is intended for professional reference only. Please refer to manufacturer’s recommendations as Encompass does not guarantee the accuracy, reliability or safety of this information. 

One of the most accurate ways to test a refrigerator’s thermistors is to use a glass of ice water.  Here is a helpful video showing the process.

With a thermistor hooked up to a multimeter, submerge into a glass of ice water. In the video, the multimeter read about 11,000 ohms prior to inserting the thermistor into the water. This is a correct reading as the current temperature of the room in the demonstration is 73°F.

When testing a thermistor, it’s important to consult a chart that states what the resistance value of the thermistor should be at any given temperature. This particular thermistor should have a resistance value of about 32,000 ohms at 32°F, which makes a glass of ice water a perfect testing mechanism.

The video shows resistance value climbing towards 32,000 ohms. As the resistance value reaches 32,000 ohms, its reading starts to slow as the thermistor reaches 32°F. It read correctly at 73°F as well as 32°F. Now, keep in mind, that these resistance values should be within plus or minus 10%. Out of range by more than 10%, plus or minus, it should be replaced.

Special thanks to Fred’s Appliance Academy for this helpful tip.