Howard B San Leon , TX December 24, 2017 Appliance: Whirlpool Upright Freezer EV200NXAW00 Whirlpool Freezer Ev200nxaw00: Ice buildup. How to replace Refrigerator Defrost Timer. With a defrost timer and thermostat. The job didn't take long, it was getting the ice and clean up that took more time than anything else Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes