Jon R Vallejo , CA May 01, 2021 Appliance: Kenmore Freezer 25321421105 Kenmore Freezer 25321421105: Ice on the bottom warm on top of the freezer. How to replace Freezer Defrost Thermostat. Best $30 investment. Replaced the defrost thermostat. The hardest part of the job was removing the food and defrosting the ice on the floor of the freezer. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes