Chertou V Neenah , WI October 05, 2014 Appliance: General Electric Refrigerator GTS18IBMARWW Ge Refrigerator Gts18ibmarww: Defost problems. How to replace Defrost Timer. Turn the timer to defrost heat is working good. changing the timer every things work good. thanks, 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes