A refrigerator in an RV is designed to maximize storage space, which means it has a variety of systems that should keep everything running smoothly and at the right temperature.
As RV refrigerators have some unique quirks, there are a few things that could go wrong with them, and at some point, you may have to troubleshoot the RV refrigerator. You must understand how your RV refrigerator operates if you want to ensure that your food and drinks stay cool. RV refrigerators work entirely differently from home refrigerators, so you must understand their characteristics.
Among the most frequently asked RV refrigerator troubleshooting questions is about the thermistor. In your RV refrigerator, a thermistor, or temperature probe, plays a vital role in regulating the temperature so that it stays where it needs to be.
Find out where your RV refrigerator’s thermistor should be located and what you should look for when checking it. Don’t be caught off guard the next time your refrigerator fails and you need to perform an RV refrigerator troubleshooting.
What is a Thermistor?
A Thermistor is a device made with a simple resistance-based thermal probe. Its resistance changes according to the air temperature in its surroundings. The heat source will be turned on or off according to the resistance measured by the control board where the thermistor is plugged.
These probes are not meant to last a very long time. As time passes, the probe in your Rv fridge starts to deteriorate and falls out of its temperature range. That’s why the refrigerator will run too cold or too hot.
Changing the thermistor position effectively rebalances the resistance and tricks the control board.
When your refrigerator runs consistently at 42 degrees, moving the thermistor to a place that gets cold slower can lead to the temperature dropping to 38 degrees before the control board turns off the heat.
Checking a Thermistor in an RV Refrigerator
You should check the thermistor when the RV refrigerator produces excess frost, and the milk turns into popsicles. It is important to test the thermistor, a resistance-based temperature sensor, before determining whether the problem lies elsewhere. Thermistor failure commonly affects RV refrigerators, resulting in too low temperatures. A replacement thermistor can be purchased cheaply, and repair guides are available online.
But before jumping into action, you must ensure your thermistor is the problem. Here are some steps to check your RV refrigerator’s thermistor.
Preparation for checking the thermistor
Good preparation is important before you can check your thermistor. Here’s what you need to do:
First step
Make sure you know what the resistance range is for your refrigerator model. A good reference value is the resistance range close to the freezing point. The thermistor’s resistance increases as it gets colder and vice versa.
Second step
Follow the instruction manual of the RV refrigerator with regards to finding and connecting the thermistor.
Third step
You need to locate the thermistor. At the back of the refrigerator, the sensor part of the thermistor is attached to one of the cooling fins, while the connection end is elsewhere. The panel with indicator lights and switches may be located behind the eyebrow board in many refrigerators.
Fourth step
Remove the thermistor. The refrigerator models differ from one another. Among the steps involved in this procedure are removing the eyebrow board, pulling the board forward, and disconnecting the thermistor cable from the board.
Checking the Thermistor
First step
Check the thermistor wires with an ohmmeter. A cheap ohmmeter can be found at most hardware stores. Two connections on the thermistor can be connected to either of the ohmmeter’s two test probes.
Second step
Resistance is measured by ohmmeters, while multimeters can measure voltage, resistance, and current. Choose the portion of the dial marked resistance (often marked with an omega symbol to indicate ohms). The dial should be turned until the largest number scale is displayed.
Third step
You can check the measured resistance on the screen of your ohmmeter. The range for that fridge model (refer to your manufacturer’s instruction manual) should be compared to the range given by the ohmmeter.
Fourth step
As long as the thermistor measures within the specified range, it is not faulty, and there must be a problem elsewhere. When the result of the ohmmeter is beyond the prescribed range indicated in the manual, the thermistor needs to be replaced.
Conclusion
Your RV Refrigerator’s thermistor is essential to keep your items fresh. It works by adapting to the ambient temperature and sending signals to the control board. The thermistor signals the control board to start the cooling process whenever the ambient temperature increases.
You should always check the condition of your thermistor by removing it from the refrigerator and checking its resistance range using an ohmmeter. Should the result is outside the range indicated in the refrigerator’s manual; it’s time to change the thermistor.
Hopefully, you won’t have to change the thermistor anytime soon! Just keep an eye on it so you’ll have an enjoyable trip on the road.
