How To Test A Dryer Thermal Fuse
If your dryer stops suddenly, it could mean a bad thermal fuse. A thermal fuse is a safety device that stops the dryer when it overheats to prevent fires.
Federal law requires these devices on all modern machines made since the 1980s. A thermal fuse melts when it overheats, unlike an electrical fuse that shorts, so it cannot be repaired. Before you replace the fuse, follow these step to test it to ensure it is the problem.
Find the Thermal Fuse
To troubleshoot the thermal fuse, gather screwdrivers, a multimeter, 1/4 nut driver, and electrical tape. The thermal fuse is commonly installed on the dryer's exhaust duct, but location may vary. Check your manual to verify the location.
Unplug the dryer cord, flip the correct breaker in the breaker box or remove the fuse. Rotate the valve on the gas line clockwise to turn off a gas dryer.
Use a screwdriver to remove the back access panel screws, or detach the clips, and set parts aside. Look for the blower cover, the large kick panel on the bottom of the dryer, and remove any parts covering the thermal fuse.
A thermal fuse is a plastic or metal quarter-sized device with two wires. Use a nut driver to detach the mounting screw, and disconnect the wires with needle-nose pliers, if needed.
Carefully detach the thermal fuse by disconnecting the wires, making note of how they connect or snap a picture. While the cabinet is open, clean lint and dust.
Test The Thermal Fuse with a Multimeter or Bypass It
A multimeter will help determine if current still flows to the device. Let the thermal fuse get to room temperature before testing. Set the multimeter display to read Rx1, or the lowest setting, and touch a probe to each of the thermal fuse wires.
A reading of 0 indicates the fuse has not blown, and any other reading means the fuse needs replacing. Reinstall good thermal fuses, and test other parts. Some other parts to test include the motor and heating oils, or get the unit serviced.
For a temporary fix, bypass the thermal fuse, if you need to dry clothes in a hurry. Bypass the fuse by disconnecting the wires and wrapping electrical tape around them. If the dryer runs smoothly when you bypass the fuse, it needs replacing.
Replace it as soon as possible with the same model when the cycle completes to avoid fires. On a gas dryer, clean the flexible vent on the rear of the dryer and the inside of the hose to prevent future damage. To learn more, contact a washer dryer repair service company.