Chris H Longmont , CO September 23, 2016 Appliance: Frigidaire Refrigerator F45ZR24JD1 Frigidaire Refrigerator F45zr24jd1: The refrigerator was not holding the correct temperature however the freezer was performing well. How to replace Refrigerator Defrost Timer. I spoke to a friend who suggested I check the defrost unit. After watching a few videos at AppliancePartsPros, I ordered a new Defrost Timer, Defrost Thermostat and Heater-Defrost. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes