Bill K Graham , NC June 27, 2018 Appliance: KitchenAid Refrigerator KFIS20XVMS00 Kitchenaid Refrigerator Kfis20xvms00: The freezer was not cooling properly. How to replace Thermistor Kit. Replaced the compressor starter and also replaced the freezer thermistor. Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes