Every dryer has more than one thermometer. These temperature sensors are designed to keep the heating process safe. Without these sensors, the dryer is at risk of overheating and even starting a fire. This is why your dryer often defaults to not heating if one of the thermometers or thermostats ceases to function. The auto-dry sensor, however, is a unique case. This sensor isn’t for safety, it’s designed to stop the dryer when the clothes inside are no longer moist and have reached the appropriate temperature for warm, dry clothes.
If the other sensors are working, a dryer with a broken auto-dry sensor, also known as a cycling thermostat, will run forever. The other sensors will keep the dryer at a safe temperature, so it will continue to run, but the auto-sense never stops the dryer from its final tumble. So if your auto-dry never stops spinning, we’re here to help you replace the faulty part that causes this. The model we’ve used as an example is a Maytag brand. If you have a different brand, the steps may vary very slightly, but this guide should be helpful to you as well.
Gather Your Supplies
The first step is always to get together your supplies. It’s always best to have your gear ready to complete the repair from beginning to end. The most important piece to have, of course, is the replacement cycling thermostat. Look up the correct replacement part number based on the brand and model of your dryer, then order the correct replacement part.
- 1/4″ Nut Driver
- Work Gloves
- Replacement Cycling Thermostat
Take the proper safety precautions when performing an electrical repair on your dryer.
Unplug the Refrigerator
Start by removing the power. Pull that giant power plug from the enormous socket in the wall, carefully so that you don’t touch the prongs. If you need to, pull out the dryer now so you can reach the plug.
Wear Work Gloves
When handling the inside of a dryer, be sure to wear well-fitting work gloves. These protect your hands from sharp panel edges, wires, and give you a better grip.
Pull Out the Dryer
Pull your dryer away from the wall so that you have room to work behind it.
Remove the Back Panel
To access the cycling thermostat, you will need to get to it through the back panel of your dryer. Here’s how to remove it:
Remove All Screws from Large Panel Perimeter
Grab your 1/4″ nut driver and remove every screw around the perimeter of the large back panel. This should allow you to pull the panel free.
Extract Small Panel Near Top
A Maytag dryer will also have a small access panel near the top of the other panel. It will come loose when you remove the other panel, specifically the one screw that goes through both panels. Catch this smaller access panel and set it aside so it doesn’t fall.
Remove Large Back Panel
Now it is safe to lift and remove the larger panel that covers the back of your dryer.
Uninstall Cycling Thermostat
Identify Cycling Thermostat
The cycling thermostat is mounted to the inside of the dryer near the lower left-hand quadrant. It is a small raised-disk-like object that is the hub of several wires. The easiest way to spot the cycling thermostat is to match it to your replacement thermostat visuall.
Test the Thermostat
Connect your multimeter leads to the cycling thermostat to discover if it is still capable of channeling a current. If the answer is no, then this is definitely the part you need to replace.
Pull Wires from Old Thermostat
The wires are connected with metal socks over prongs, which means you can quickly pull them loose. Wear your gloves as you pull out the wires, and be gentle so as not to damage the wires you disconnect.
Remove Mounting Screw
There is a single mounting screw securing the cycling thermostat to to the dryer housing. Remove it and set the screw aside somewhere safe.
Extract the Old Thermostat
You can now remove the old cycling thermostat. We suggest you recycle as an electronic component.
Install the New Cycling Thermostat
Fit Tab Into Slot
Take the new cycling thermostat and fit the one tab into the slot-hole available for it. This will allow the thermostat to sit securely, aligned with the screw hole.
Secure the Mounting Screw
Add the mounting screw back where it goes and twist to secure. No need to over-tighten, but make sure the screw is firmly in place.
Reconnect the Wires
Now it’s time to put the wires back. Start by placing the red-only wire into the top slot. Then add the red-and-white wire to the bottom slot. The purple wires can be attached to any of the smaller prongs.
Return the Back Panel(s)
Align Back Panel Over Pipe
Now it’s time to reinstall the back panel. Lift it up so that the slot in the bottom fits over the pipe in the lower-center of the dryer, for Maytag designs. Fit the back panel into place and prepare to re-secure.
Align Small Access Panel
Snag the small access panel and fit it just underneath the large panel and hold them both in place.
Apply First Screw
Fit and secure the first screw that attaches the small panel and the back panel together.
Return Rest of Mounting Screws
Then attach the rest of the mounting screws around the perimeter of the back panel.
Test Your Success
Congratulations, your dryer is reassembled and should be ready to go. It’s time to test your success. Plug the dryer back into the wall and push it into place. Be sure to make sure your flexible duct is straightened out and in good condition when you push the dryer back. Now dry some clothes. Set your dryer to auto-dry with a few pieces of damp clothing inside. If the dryer senses when the clothes are dry and stops, give yourself a pat on the back.