Thermistor Problems?

Four primary components make up modern refrigerators and freezers, but there are dozens of additional small parts that work together to keep your food cold and fresh. One of the most important appliance parts sits quietly behind the scenes: the thermistor. Never heard of it? You are not alone! Many homeowners never hear about a thermistor until a cooling issue appears. Therefore, understanding the importance of this part and the warning signs it gives when it needs attention will help keep your refrigerator running smoothly.

What Does a Thermistor Do?

A thermistor measures the temperature inside the refrigerator and freezer. It is an important job, because keeping food safe and free from bacterial growth requires that the refrigerator be kept at 37 to 40 degrees Fahrenheit and the freezer at 0 degrees Fahrenheit. How does a thermistor do that? As the interior of the refrigerator or freezer warms or cools, the thermistor (which is essentially an electrical resistor that reacts to temperature) changes the electrical flow to the control board. The control board then adjusts the compressor and fans to help maintain the desired temperature.

Accurate temperature readings help fresh produce remain crisp, allow dairy products to hold their texture and flavor, and keep frozen items solid without frost buildup. Without reliable temperature data from the thermistor, a fridge loses its ability to keep food at safe temperature levels, causing unwanted freezing or spoilage. As a device without moving parts, most thermistors last a long time.

Signs of a Failing Thermistor

Knowing the signs of a thermistor failure will keep your foods free from spoilage. When the thermistor no longer reacts properly to temperature changes, the control board responds with the wrong adjustments. This failure to communicate causes the following symptoms:

• Uneven cooling: Frozen food in the refrigerator section, or warm spots in the freezer.
• Temperature swings: Hot or cold swings with ice buildup in places other than the refrigerator.
• Changes in motor/compressor run times: Longer or shorter run times with fans cycling at the wrong times.
• More energy use: Rising energy bills due to longer refrigerator run times.

If you are noticing any of these problems, you can purchase a refrigerator/freezer thermometer and observe for yourself the temperatures inside your appliance. If adjusting the controls to reach the desired temperature does not help, it’s wise to have a professional take a look. At River City Appliance, our trained technicians test the refrigerator and freezer, diagnose the problem, and replace the thermistor if needed. No matter what the problem, we can quickly restore proper temperature control for your refrigerator and freezer.

Keep Your Fridge Running Right!

Now you understand how a properly working thermistor supports consistent cooling, energy efficiency, and food safety. If your refrigerator shows signs of temperature trouble, River City Appliance is here to help! Homeowners across the greater Sacramento area trust River City Appliance for reliable service, honest recommendations, and repairs that bring appliances back to peak performance. Contact us by phone or online today!