Why doesn't my Whirlpool Dryer Heat?
ANSWER Hello Sam,
If you have verified the power supply to the unit to be correct, the issue will be one of the following components: Thermal Fuse: The thermal fuse is a non-resettable safety fuse that is designed to break electrical contact to the dryer’s burner or heater if the fuse becomes too hot. This fuse will often burn out due to clogged ducting or a defective cycling thermostat. The thermal fuse is the most common cause of a dryer that has no heat. Test: Disconnect all connecting wires and check for continuity across the two wire contacts. There should be no resistance measured (a closed circuit, allowing electricity to flow). Hi-Limit Thermostat: The hi-limit thermostat is a safety switch or series of two thermostats that will break electrical contact to the dryer’s burner or heater if it senses that the dryer has become too hot. The hi-limit thermostat will cycle the burner or heater off if the ducting has become clogged blocking proper airflow. Test: Disconnect all connecting wires and check for continuity across the thermostat or sensor set. (Look at your dryer's wiring diagram for test points.) Thermal Cut-Off:The dryer’s thermal cut-off is similar to the thermal fuse and the high limit thermostat it will break electrical contact to the dryer's burner or heating element if it senses that the dryer is reaching an un-safe temperature. The thermal cut-off is a set of two thermostats, which will not reset once cool. The thermal cut-off needs to be replaced as a set. If this set of dryer parts fails you will need to check your dryer and home ducting for clogging as well as check that the dryer’s cycling thermostat is operating properly. Test: Disconnect all connecting wires and check for continuity across the terminals. The thermal cut-off should be closed (allowing current to flow) at room temperature.Cycling Thermostat: The cycling thermostat is responsible for cycling the dryer’s heat source on and off to maintain a target temperature set at the timer or with a temperature selection switch. Test: Remove all connecting wires and test for continuity. There should be no resistance measured when the dryer is cool (a closed circuit, allowing electricity to flow). Timer: The dryer’s timer routes electricity to the correct dryer components or system at the proper time. Timers are expensive, rarely fail, and are often misdiagnosed. The timer should be allowing electricity to flow to the dryer’s burner or heating element and motor when needed. Test: Use your dryer’s wiring diagram to check for voltage being supplied to the heating circuit or motor circuit. Heating Element: A heating element is used in electric dryers to generate the heat needed to dry your clothes. Almost all heating elements require 240 Volts to function correctly. Sometimes the heating element can short, allowing contact to ground. If this does not trip the circuit breaker, it will effectively bypass the cycling thermostat and cause the heater to never cycle off as long as the dryer is running. Test: Remove all connecting wires and check for resistance across the two terminals of the heater. Some resistance should be detected allowing the heater to perform its work. If an open circuit is detected, the heater needs to be replaced. Also check each of the heater's contacts to the heater housing. There should be no connection. If the heater tests okay, check the connected thermostats for continuity and your home's power supply for full 240-volt supply.
Answered by AppliancePartsPros.com | Saturday, February 09, 2013