Your freezer does its best to keep a consistent temperature. Part of its freezing cycle includes a heater that stops the temperature from getting too cold or stops frost from building up in your appliance. But if the defrost thermostat has shorted or become broken, your freezer can’t regulate its own temperature anymore.
Depending on the cycle’s position when the damage occurred, your heater might never come on or might never turn off. Either situation is bad for your freezer. If you want to replace your Whirlpool refrigerator’s defrost thermostat yourself, all you need to do is order a replacement part #WPW10225581. Then make sure you have two wire nuts or butt connectors on hand and follow these steps:
1. Unplug the refrigerator.
The first step in every appliance repair procedure is turning off the appliance. This keeps you safe from electrocution, even if you don’t plan on handling any wiring. During the course of this repair, you will be cutting wires and creating new wire connections. Unplugging the refrigerator, or flipping the circuit breaker if the appliance is directly connected to your house’s power, is essential.
2. Remove the refrigerator’s back panel.
The defrost thermostat is located behind the back panel in the freezer section. Once your refrigerator has been unplugged, the next step is to give yourself clear access to that back panel.
First, open the freezer side’s door and remove the ice machine’s bucket. Next, remove each of the shelves off of the interior pegging. Also, take the bins out by pulling them forward and lifting them up off the bin guides. Set all of this interior hardware to the side.
Then remove the rails and pegs. Keep track of the shelves’ orientation by taking a picture. This will help you reassemble the wide and narrow rails on the correct sides once the thermostat has been replaced. Then loosen the screws holding the rails in place and set them aside. The shelves’ mounting clips also need to come off. For most Whirlpool models, all you need to do is pull the pegs up off of their support structures to loosen them.
Once the interior parts are removed, remove the plastic light cover near the top of the back panel. Squeeze the plastic to twist it off the mounting tabs and set aside. Unscrew the lightbulb if you think it might be in the way.
Then loosen and remove the six screws securing the back freezer panel. Lift the back panel off the two tabs near the middle of the freezer. Also, lift it up from the bottom so it bows slightly. This pushes it free of the clips and gives you room to pull the top of the panel from behind the light. Once you have pulled the panel free, carefully set it aside.
3. Remove the thermostat.
Locate the thermostat near the evaporator. It is attached only by a metal clip, so carefully work the part free. Next, cut the red and black wires connected to the thermostat.
Prepare the wires for the connection: strip approximately a half inch from the end of the red and black wires.
4. Install the new defrost thermostat.
Before you get started, make sure the red and black wires on the new part are adequately stripped so you can connect them to the refrigerator. You need approximately half an inch of stripped wire on both the red and black ends.
First, connect the wires. Red should connect to red and black needs to connect to black. While you can use butt connectors, the easiest connecting tools are wire nuts. With wire nuts, all you have to do is place the raw ends of two wires together and twist one wire nut over the two ends. The pressure and tight quarters in the wire nuts force the stripped wires to touch and conduct electricity.
If you have butt connectors, they can also work. Stick the unstripped red wire from the defrost thermostat into one end and crimp the connector end tightly over it. Stick the other red wire from the refrigerator into the other end of the connector and crimp it securely in place. Use one butt connector for the red wires and the second for the black wires.
Once the wires are connected, attach the new defrost thermostat onto the evaporator coil using the clip. If there is excessively long wire, carefully tuck it into the empty space by the evaporator. Make sure it’s completely out of the way so it doesn’t catch on the back panel.
5. Reassemble the refrigerator.
Start by reinstalling the back panel. First, slide the top lip into place behind the light. A flathead screwdriver can help you wedge it into place. Line up the middle of the panel with the mounting clips, and then press the bottom into place. Make sure the whole panel is pushed gently straight. Then retighten the six screws holding the panel in place.
Next, screw in the light bulb if you removed it and reattach the plastic light cover.
Then, reinstall the rails and pegs. As you install the rails, check the picture you took earlier to ensure the wide and narrow rails are reinstalled on the correct sides and in the correct orientation. As you reattach the shelf support pegs, make sure you firmly line them up without overtightening or twist.
After that, reinstall the freezer bins and shelves onto the supports.
Then guide the ice machine bin back into place over the ice machine. Make sure the bin fully locks into place or you might not be able to shut the door. Plug the refrigerator back in.
Once your refrigerator’s freezer returns to a normal freezing cycle after being unplugged, your new thermostat should start regulating the temperature. Check the appliance in roughly half an hour to make sure the heater is operating without overpowering the machine. For more hands-on appliance repair guides, go to Flamingo Appliance Service here. Our expert technicians can also help you with trickier repairs if you schedule a service call.