How To Check A Thermal Fuse On An Electric Dryer

If your dryer runs, but it isn't heating, test the thermal fuse. The thermal fuse is a small safety device that cuts off the dryer when it reaches a set temperature.

Unlike a thermostat, they don't reset themselves, which means they need replacing. Federal law requires thermal fuses on all dryers. Here are some tips to test for a burned thermal fuse on an electric dryer.

Locate the Thermal Fuse

You will need a multimeter, electrical tape, and a screwdriver for this project. Turn off the electricity from the breaker box, and unplug the cord, which should be on the wall behind the dryer.

Move the dryer from the wall slightly. Look for the thermal fuse on the front toe panel, or the rear panel of the dryer.

The thermal fuse is a white device with two wires attached to it.  If you find the fuse on a rear panel, detach the screws on the panel with a screwdriver to access the thermal fuse. If the fuse is on the front panel, use a screwdriver to depress the clips, which should be located four inches from the panel edge.

Test with a Multimeter

A multimeter is a digital or analog device with two test probes that detects whether or not there is a flow of electricity. It measures OHMs, or units used to measure electrical resistance. 

A digital multimeter is easier to use than an analog because you don't have to set a dial. Let the thermal fuse get to room temperature. Set the multimeter to RX1 (resistance times one), the lowest setting.

Unhook the thermal fuse wires by removing the wire nuts by hand, then touch each wire with the test probe on the multimeter. You should get a reading of 0 when the thermal fuse is at room temperature.

A reading of 0 means the circuit has continuity, and it doesn't need replacing. If the fuse is damaged, the needle won't move, or the digital display stays the same.

Bypass the Thermal Fuse

Another way to test the thermal fuse is to bypass it. However, this should only be a temporary means of testing the dryer, since doing this constantly increase the risk of fires.

Unhook the thermal fuse wires, and wrap electrical tape around them. Check the lint trap, then dry a load of clothes. If the dryer dries the clothes, the fuse is damaged.

Replace the thermal fuse, then wash and dry a load of clothes to test the replacement.  If you don't trust your skill to replace the fuse, or the dryer still isn't working after you replace the fuse, contact an appliance repair service like ASAP Appliance Repair, Inc.