How to Replace the Defrost Thermostat in a French-Door Refrigerator

Authorized Service
September 9, 2019
Refrigerator Repair

Defrosting is an important feature for all modern fridges and freezers. There are several components that make smart defrosting possible, and one of these is the defrost thermostat. If your defrost thermostat is no longer detecting the temperature and sending defrost signals to the system, then it will need to be replaced.

This repair will require some work with wires, but it can be done by a careful amateur as long as you take the correct precautions. 

1) Supplies

Start by collecting your supplies. This repair will require a few items from your toolbox or you may need to swing by the hardware store for anything you don’t use regularly at home.

  • Replacement Defrost Thermostat
  • Screwdriver
  • Wire cutters
  • Wire InsullationStripper
  • 2 Wire Nuts
  • Silicone Sealing Gel
  • Zip Tie

2) Cut the Power to Your Fridge

With any appliance repair, always start by cutting the power. If you can reach the refrigerator’s plug, unhook it from there. However, if the plug is too far back or hidden by your kitchen design, you can flip the kitchen breaker instead. Confirm that your fridge is fully un-powered by opening the door so see if the light comes on. If it does not, you are safe to continue the repair. 

3) Empty the Freezer

For a french-door style refrigerator of most major brands and several minor brands (Whirlpool, Kenmore, KitchenAid, Maytag, Roper, Estate, Amana, Crosley, Inglis, and Ikea), the thermostat is located behind the back panel inside the freezer. So you’ll need to start by pulling everything out of the freezer.

  • Remove All Food Items

Remove all frozen food items. Load them into a cooler or your fridge compartment if possible to keep them cool. If you don’t have a cooler or room in your fridge, keep them close together on the counter to chill each other.

  • Remove Shelves and Drawers

All shelves and drawers must come out to remove the back panel. Carefully unhook any latches and remember to lift-and-pull for most mounted shelves.

  • Remove the Light Cover

Don’t forget the light cover. Unscrew or unclip the freezer light cover and set it aside on the counter nearby. 

4) Remove the Freezer Back Panel

The next step is to carefully remove the back panel of the freezer.

  • Unscrew the Back Panel Fastener Screws

Start by unscrewing the several screws around the edge of the back panel. Use whichever screwdriver is appropriate for the type of screws you find there.

  • Lift the Panel Off the Mounting Tabs

The mounting tabs point upward and mount in the center or sides of the panel. So you’ll need to lift the panel upward to pull it free from the freezer housing.

  • Pull the Panel Out

Carefully pull the back panel out of the freezer and set it aside where it won’t be in the way. 

5) Uninstall the Old Defrost Thermostat

This is where we get technical. You will need your wire cutters to remove the old defrost thermostat.

  • Identify Thermostat and Wires

Start by identifying your thermostat. Assuming you have the replacement part, you know what the thermostat looks like. It should be clipped to the top of your evaporator coils and connected to two wires, red and black.

  • Cut the Wires Close to the Thermostat

With your wire cutter, clip the wires off, close to the thermostat, leaving plenty of unconnected wire hanging from the fridge.

  • Unclip Thermostat from Evaporator

Unclip the old defroster thermostat from the top of the evaporator coils and throw it away. 

6) Install the New Defrost Thermostat

Next, you will need to prepare the new thermostat and the old wires and connect them. If you’ve worked with wires before, this should be a simple process. If you haven’t, consider watching a video to show you play-by-play how it’s done.

  • Strip All 4 Wire Connections

Start by stripping about 1/4 inch of insulation off each wire. There are four wires to strip and prepare for connection: 2 on the new thermostat and the 2 you clipped from the old thermostat. Strip a small section of insulation from all four using the correctly sized aperture in your wire stripping tool.

  • Use Wire Nuts to Connect the Old and New Wires

Wire nuts are used to ensure a safe connection between two twisted-together wires. Use your wire nuts to carefully and firmly connect the red thermostat wire to the red fridge wire, and the black thermostat wire to the black fridge wire.

  • Fill Nuts with Silicone Sealant

To make sure those wire nuts stay in place, use a dab of silicone gel inside and around each wire nut. It will dry into a firm yet flexible sealant.

  • Clip the Thermostat Onto the Evaporator

Once your wires are secure and sealed, clip the new thermostat into place on top of the evaporator coils. Congratulations, you just finished the hardest part. 

7) Replace the Back Panel

With the new thermostat installed, it’s time to put your freezer back together. Grab your top panel and prepare to return it into place.

  • Line Up Top and Bottom

Start by slotting the top of the panel just behind the air duct housing, then align the bottom just behind the drip tray.

  • Set Onto Mounting Tabs

Carefully adjust the panel until it sets correctly down onto its mounting tabs. If it does not set correctly, the panel will be pushed out by the tabs instead.

  • Return and Tighten Screws

Return the screws and tighten them into place. Hand-tight is fine, no need to wrench them shut. 

8) Refill Your Freezer

Finally, you can get your freezer back into its usual configuration of shelves, drawers, and frozen food.

  • Return Light Cover

Grab the light cover and reinstall it now that the back panel is in place. Use the same clip or screw that was released when you removed the cover.

  • Return Shelves and Drawers

Return all the shelves and drawers back to their proper place in the freezer. This could also be a good time to rethink your freezer storage arrangement.

  • Bring Back the Power

Before you load up all the food, plug your fridge back in or flip the breaker back on. This will ensure that your freezer can go right back to keep the contents cold.

  • Test Your Freezer

Close the freezer and wait a few minutes. If you hear the appliance start-up and begin cooling, it’s safe to put the food back in. Open the freezer and put your hand it to test if it is creating new cold.

  • Reload Frozen Food

Last but certainly not least, get all your frozen food back into the freezer. The food will actually help your freezer get back down to its optimum temperature and stay there.


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