Daniel M Eagleville , CA March 10, 2015 Appliance: Whirlpool Refrigerator CT21GKXKQ01 Whirlpool Refrigerator Ct21gkxkq01: Refrigerator would not stay cold. How to replace Thermostat. Easy fix in less than 10 minutes. I replaced the thermostat control. I first shorted the two wires that went to the control and let it run for 1 hour. The temperature was dropping and the freezer was freezing. 11 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes