If your dryer will run but does not produce any heat, there is likely a problem with the dryer's heating element or thermal fuse. The thermal fuse is a safety feature against overheating, and will often blow if lint buildup in the trap or the dryer hose prevents proper air flow. Checking the fuse is easy if you own a multimeter or ohmmeter. If you don't, there is still a way to troubleshoot your dryer.
Testing a Dryer Thermal Fuse
Checking the thermal fuse is the fastest way to determine if it is why the dryer will not generate warm air. The best way to test a thermal fuse is by testing it with a ohmmeter or digital multimeter. For an ohmmeter, set it to "Rx1." This will immediately gauge whether the thermal fuse is allowing the passage of electricity to the heating system or not.
The probes of the digital multimeter or ohmmeter need to touch the edges of the thermal fuse to read it correctly. Once the connection is made, a reading should appear on its screen. If the needle on the ohmmeter changes place to 0, the thermal fuse is fine and does not need to be replaced. If the needle does not move, the fuse is bad and needs to be replaced.
Bypassing a Dryer Thermal Fuse
If you do not have access to a multimeter or ohmmeter, you can momentarily bypass the thermal fuse. While bypassing the thermal fuse is easy, it is not something that should be done to operate the appliance beyond troubleshooting if you do not have access to a multimeter or ohmmeter. Operating a dryer with a bypassed thermal fuse is both unnecessary and unsafe, so a bypass should only be done long enough to troubleshoot a potential problem. Even short usage without a thermal fuse in place could result in irreparable damage to the appliance or injury to yourself.
Unplug the Dryer and Open the Appropriate Panel
Disconnect the dryer from the electrical outlet before beginning any troubleshooting. Only once all power has been cut to the dryer is it safe to proceed. As varying models and brands have differing locations for the thermal fuse, use the schematics in the owner's manual that came with the dryer or search online for a manual if you don't own one.
In most cases, the thermal fuse will be located behind the rear dryer panel or bottom kick panel. Depending on the model, kick panels can be removed by releasing the two metal clips holding it in place or by using a flathead screwdriver to pop the panel off. To remove the rear panel, simply remove the four corner screws securing it in place.
Locate and Bypass the Fuse
Locate the thermal fuse. The thermal fuse will look like a thin strip of white plastic with a wire coming out of each end. In order to bypass the thermal fuse, use electrical tape to tape the two ends together. The thermal fuse will then be bypassed. Turn the dryer on to a heat cycle for no more than 90 seconds.
Replace the Fuse if Indicated
If the dryer starts to run warm once the fuse is bypassed, the fuse was the problem and needs to be replaced immediately. If it still does not operate correctly, the issue is likely a faulty heating element. Replace the thermal fuse immediately if the dryer operates normally with the thermal fuse bypassed.
Undo the Fuse Bypass Immediately
Bypassing the thermal fuse is a last resort and shouldn't be necessary if you have a multimeter or ohmmeter – or if you can remove the fuse and take it to a local repair shop for testing. If you do bypass the fuse, remember to remove the electrical tape bypassing the dryer immediately after the test.
If the problems persist after replacing the fuse or the heating element, you may require a professional technician to repair the dryer. Never operate a dryer without a working thermal fuse in place.