Defrost Thermostat WP2321800 in a Whirlpool Fridge Replacement

Is your refrigerator no longer cooling like it used to, or are you noticing frost buildup inside the freezer? It could be a faulty defrost thermostat causing the issue. Luckily, replacing it yourself is a simple task that can save you time and money—plus, there’s a step-by-step video guide right below to walk you through the process!

Looking for the right part? Enter your appliance model number below to find the exact match and get your appliance running like new again!

Having issues with your refrigerator not cooling properly? An excess buildup of frost or ice on the rear wall inside the freezer? Or maybe the freezer section is cold but the fresh food section doesn’t seem to be getting cold enough? There’s a good chance your defrost thermostat could be faulty. Replacing this small but important defrost thermostat is thankfully an easy fix you can do yourself in just a few minutes with some basic tools and a new part.

Watch the repair here: How to replace a defrost thermostat

The information in this article may not apply to your specific appliance model. We recommend consulting your manufacturer’s documentation or contact us with any questions.

What is the defrost thermostat?

The defrost thermostat is a safety component that regulates the defrost cycle in your refrigerator. It is located on the refrigerator evaporator coil.

Every 6-8 hours, a defrost heater kicks in to melt frost on the coils. It helps the fridge maintain airflow and cooling efficiency. The thermostat acts as a control switch, cutting power to the defrost heater if it senses things getting too warm during defrosting. This stops overheating and protects the plastic parts from damage.

When this thermostat stops working properly, you’ll notice things like:

• Reduced cooling capability
• Freezer is OK but the refrigerator section not getting cold
• Excess moisture or frost buildup on the back wall of the freezer
• Higher electric bills from fridge running excessively

Replacing this simple and inexpensive defrost thermostat is usually all that’s needed to resolve these types of issues.

Tools and materials needed

• Defrost thermostat WP2321800-Take your model number to AppliancePartsPros.com to locate the correct part. 
• 1/4-inch nut driver
• Wire strippers
• Electrical tape
• 2 butt connectors
• Crimping tool

Safety first

Your safety should always be the top priority when performing any appliance repair. 

• Always power off and unplug your appliance or switch off the circuit breaker before attempting any maintenance or replacement work. This keeps you safe by preventing any risk of electric shock. 
• If the appliance has recently been used, give it plenty of time to cool down before working on it. 
• Take your time and don’t rush while working to prevent accidents and personal injuries.
• Work in a well-lit area so you can clearly see and access appliance parts.
• Keep your workspace free of clutter and other obstacles. Keep children and pets away from the work area.
• Never work on internal parts with wet hands. Make sure the work area is completely dry.
• Check the user manual to see if there are specific installation or safety instructions related to your appliance or replacement part. 
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause personal injury.
• Wear insulated work gloves to protect your hands from sharp metal parts and debris.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Don’t test live voltage with a multimeter if you’re unfamiliar with how to prevent short-circuiting.
• Consider wearing safety glasses and/or a dust mask when working with chemicals, dust or a large amount of debris to prevent irritation or injury.

Disassembly and Removal Steps

1. Open the freezer door.
2. Slide out the ice bucket and set it aside.
3. Using your 1/4-inch nut driver, remove the bottom screw first, then the two top screws.
4. Gently pull the ice maker forward and unplug the harness by pressing the locking tab and pulling the plug apart.
5. Set the ice maker aside.
6. Lift up the right side of the shelf and push it inward.
7. Then lift the left side all the way up and slide the shelf out.
8. Remove the screws securing the back panel using your 1/4-inch nut driver.
9. Remove the ground wire clip on the left side next to the water inlet tube.
10. Grab the cover panel, tilt it forward, and wiggle it side to side until it’s free.
11. Watch out for the wiring plug—push it gently through the opening if it’s in the way.
12. The defrost thermostat is clipped onto a copper tube near the evaporator.
13. Unclip it and pull it into the open to work on it.
14. Use wire strippers to cut both wires connected to the thermostat.
15. Strip about 1/4″ of insulation from each wire end on both the fridge and the new thermostat.
16. Trim the wires to match the length of the old harness.
17. Strip the ends so they’re the same length as the ones you just cut.
18. Twist the wire ends together and slide on the butt connectors.
19. Use your crimping tool to crimp both sides tightly—give a light tug to make sure they’re secure.
20. Wrap the connectors with electrical tape to insulate and protect them.
21. Clip the new defrost thermostat back onto the copper tube in the same spot you removed the old one.

Installation and Reassembly Steps

1. Slide the panel into place over the openings.
2. Reconnect the wiring plug and ground wire.
3. Make sure the panel is flush with no gaps showing.
4. Secure it with the screws using your nut driver.
5. Slide the right side of the shelf into the cutout, then lower the left side and pull it into position.
6. Start by loosely threading in the front screw.
7. Reconnect the ice maker plug and slide the harness into its cutout.
8. Place the water inlet tube into its opening in the back.
9. Hang the ice maker on the front screw, then install the rear screws.
10. Tighten all screws to secure the ice maker.
11. Slide the ice bucket back under the ice maker.
12. Plug the refrigerator back in. Close the freezer door.
13. Wait a few minutes and check if it’s cooling properly again.

More information

Thanks for reading! We hope this guide helped you replace the defrost thermostat in your refrigerator. 

If you still need some replacement parts, grab your model number and head over to AppliancePartsPros.com. We offer over two million parts and most orders arrive in two business days. If you need some help with finding the right part or placing an order, you can contact our team at 1 (877) 477-7278.

While you’re waiting for your new part to arrive, you can explore our DIY blog and watch thousands of video tutorials on our YouTube channel.

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