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The Thermistor has failed or is failing. It is the temperature sensor that is basically your electronic thermostat.
Troubleshooting Guide: U-Line Refrigerator Error Codes
U-Line refrigerator troubleshooting begins with cracking the codes. Let's take a look at
U-Line brand error codes.
Error Code ER
Diagnosis: Thermistor 1 is open
Explanation: The U-Line refrigerator error code ER is alerting you to a failed thermistor. Thermistors are used for various temperature readings. These provide reliable temperature readings using a resistance which varies based on surrounding temperatures. If you have a
U-Line wine cooler, for example, it will include ambient temperature surrounding the refrigerator unit.
If the thermistor 1 fails, the refrigerator will continue to operate on a preset 10 minutes on and 30 minutes off time interval.
Solution: Use an accurate ohm meter to test the thermistor. If the thermistor is defective, have it replaced.
https://www.google.com/search?q=uline+u-2115wcs+thermistor
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