J S Adair , IA June 19, 2017 Appliance: Frigidaire Refrigerator LFHT1513LW5 Frigidaire Refrigerator Lfht1513lw5: The freezer compartment would frost after a couple weeks of operating. How to replace Defrost Thermostat. Thanks to the the how to videos the repair went well.I replaced the defrost thermostat and the defrost timer just in case the thermostat wasn't the problem. 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 1-2 hours