Carrie C Anderson , IN August 08, 2015 Appliance: General Electric Refrigerator TBX18ZHCR Ge Refrigerator Tbx18zhcr: Would not defrost/. How to replace Defrost Heater. Replaced the heater part in the freezer. now the bottom & top are cold! thanks Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes