John K Mesa , AZ June 05, 2018 Appliance: Whirlpool Electric Dryer WED9400SZ0 Whirlpool Dryer Wed9400sz0: Whirlpool duet dryer not heating. How to replace Thermal Cut Off. Replaced heater coil and thermostat. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes