A thermal switch on an electric dryer completes a circuit and remains open, or on, while the dryer is in operation. The switch leads to a heating element that produces hot air to dry clothes as they tumble in the dryer. A sign of a faulty thermal switch is that the clothes are damp and cold after the dryer finishes a timed cycle. You can easily test a thermal switch for faults with a simple jumper wire.
Things You'll Need
- Jumper wire
- Needle-nose pliers
- Small flat screwdriver
Turn off the dryer and let it cool before testing the thermal switch. On Maytag, Whirlpool and Kenmore dryers, the switch is on the fan housing. Older GE dryers place them under the lint filter. Newer GE dryers install them on the front of the fan blower.
Remove the wires from each end of the thermal switch. The wires attach to the switch differently depending on the model. Use needle-nose pliers to unwind the wiring from each end or a small flat screwdriver to remove screws that connect the wiring on each end to the component.
Connect a jumper wire to each end of the switch to bypass the switch. A jumper wire is an insulated copper wire. Any small copper insulated wire is useful in this procedure. Auto supply stores sell jumper wires in many lengths.
Wind one end of the jumper wire to the wire that was on one end of the switch. Wind the two copper ends together in a clockwise direction. Place a wire nut on the junction by pushing it on and turning clockwise at the same time. Repeat this procedure for the wire on the other end of the switch.
Turn the dryer on and wait for about five minutes. Open the dryer door and put your hand inside after it quits turning to see if the air is hot. If the air is heating, the switch is not working properly and needs replacement.
Replace the switch with either a new one or the old one that is working. Detach the jumper wire from each end of the switch wiring by removing the wire nuts and untwisting the wires in a counterclockwise direction. Reconnect the wiring to each side of the switch.
Tips & Warnings
- Bypassing the thermal switch and receiving no hot air inside the dryer indicates that the switch is in working order.
- Check the dryer exhaust hoses and vents for blockages that cause the lack of heat. This is the most common cause of limiting heat in an electric dryer.
- Photo Credit Jupiterimages/Comstock/Getty Images
How to Test a Dryer Door Switch
Many people may not know this, but dryers have a door switch that makes it impossible for them to operate when the...
How to Wire Electrical Switches
Wire electrical switches yourself and save on electrician fees. A switch connects and disconnects a wire carrying electricity. When switches are "off"...
How to Test a Thermal Cut Off for a Dryer
The thermal fuse, also known as the thermal cutoff, is designed to shut the dryer down if the temperature becomes too hot....
How to Reset a Thermal Switch in a Water Heater
If your water heater has stopped heating, a tripped thermal switch may be to blame. In water heaters and many other types...
How to Test a Thermal Overload Switch
If one of your home appliances has suddenly stopped producing heat, don't rush out to start shopping for a new appliance just...
How to Install a Fan Thermo Switch in a Honda Accord
The thermo switch in a Honda Accord is located either in the bottom of the radiator or in the coolant pipe located...
How to Check the High Limit Switch on a Trane
The high limit switch (also called a main air limit switch) in a Trane furnace is a safety device that is supposed...
How to Install a Thermo Coupling
Learning how to install a thermo coupling only takes a few minutes and can save you hundreds of dollars in plumbing repair...
How to Wire a Thermal Switch
Thermal switches, also known as thermostat switches, are used in applications where you would want to control an electric circuit based on...
How to Repair a Microwave's Thermal Switch
Microwave ovens use thermal switches, or fuses, to control the amount of heat inside the appliance. When this fuse blows, the microwave...