Test and Replace Your Whirlpool Refrigerator’s Flipper Mullion for Optimal Cooling

The flipper mullion, or mullion rail, is an essential part of your Whirlpool French door refrigerator, helping maintain a cool environment by sealing the gap between the two doors. Over time, the mullion can wear out or get damaged, which makes your refrigerator work harder to keep things cold. Here’s a step-by-step guide to testing and replacing the flipper mullion to keep your fridge efficient.

Signs That Your Flipper Mullion Needs Replacement

Recognizing the signs of a failing flipper mullion can help prevent temperature fluctuations and maintain energy efficiency. Here are some indicators that it might be time for a replacement:

• Increased Frost Buildup: If you notice frost or condensation on the edges of the refrigerator or freezer compartments, the mullion may not be sealing effectively, allowing warm air to seep in.
• Higher Energy Bills: A damaged mullion rail can make your fridge work harder to maintain a cool temperature, increasing its energy consumption. If your energy bills are suddenly higher, it could be due to the refrigerator running more frequently.
• Uneven Cooling: When the mullion isn’t working correctly, the refrigerator might struggle to maintain a consistent temperature, resulting in warmer areas that affect food freshness.
• Visible Wear or Damage: Over time, the mullion may crack, warp, or show other physical signs of wear. Regularly inspect the mullion for any visible issues, especially if the refrigerator is older or frequently used.

Identifying these signs early can help you address the issue promptly, ensuring your refrigerator stays efficient and your food remains fresh.

Tools and Materials Needed

• Multimeter
• Nut driver
• Flathead screwdriver

Safety Precautions

Ensuring safety while working on appliances is essential. Here are important tips to follow:

• Unplug or Switch Off Power: Before any maintenance, disconnect the appliance from power. This reduces the risk of electric shock.
• Use Insulated Gloves: Protect your hands from sharp parts, pinching points, and any debris.
• Work Carefully and Slowly: Taking your time helps prevent accidents and injuries.
• Ensure Good Lighting: A well-lit workspace allows you to see and handle small or intricate parts with greater precision.
• Clear Your Workspace: Remove clutter, and keep children and pets out of the area for safety.
• Avoid Wet Hands: Only handle internal parts with dry hands to prevent any electric shock.
• Consult the User Manual: The manual may have specific safety instructions for your refrigerator model.
• Handle Parts with Care: Avoid using too much force, which can damage parts or cause injury.
• Wear Safety Glasses: Protect your eyes when dealing with dust, chemicals, or large debris.
• Allow Cooling Time: If the refrigerator has been in use recently, give it time to cool before working on it.
• Document Wiring: Take photos or make notes of connections before disassembling to simplify reassembly.
• Avoid Direct Contact with Exposed Wires: If contact is necessary, use a non-conductive tool or wear insulating gloves to avoid electric shock.

How to Test and Replace the Flipper Mullion on a Whirlpool Refrigerator

Accessing the Mullion Wiring

1. Unplug the refrigerator or turn off the breaker to disconnect power.
2. Open the left door of the refrigerator and locate the flipper mullion.
3. Flip the mullion to the open position to access the mounting screw on the middle hinge.
4. Use a 1/4-inch nut driver to remove the mounting screw.
5. Push the mullion upward from the bottom to release it from the upper and lower mounting tabs.
6. Move the mullion away from the door to detach the middle cover held by the screw.
7. Disconnect the power connector from the mullion.

Testing the Flipper Mullion

1. Set your multimeter to measure resistance (ohms).
2. Place the multimeter leads on each terminal connected to the mullion.
3. Check for a reading between 20 and 30 ohms.
   • If the reading is outside this range, the mullion needs replacement.
   • If the reading is correct, proceed to the voltage test.

Testing for Voltage

1. Plug the refrigerator back in and turn on the power.
2. Clear any “PO” or “PF” error messages by pressing and holding the two buttons farthest to the left on the user interface until a countdown from 3 appears.
3. Ensure the display flashes “01.”
4. Press the fifth button from the left (with a plus sign) to advance to test 35, which runs the vertical mullion heater.
5. Confirm the display shows “01.” If it shows “02,” press the options button to change it to “01.”
6. Set your multimeter to read DC voltage.
7. Place the multimeter leads in the connector coming from the door.
8. Check for a reading of 12-15 volts DC.
   • If the voltage is not within this range, the user interface in the door may need replacement.

Replacing the Flipper Mullion

1. Unplug the refrigerator or turn off the breaker to disconnect power again.
2. Connect the flipper mullion heater harness to the harness coming from the door.
3. Align the mullion with the center cover and the upper and lower mounting tabs.
4. Slide the mullion down, ensuring all mounting points are correctly aligned.
5. Use the 1/4-inch nut driver to reinstall the screw that secures the center cover to the door.
6. Plug the refrigerator back in or turn the breaker back on to restore power.

Also read: Step-By-Step Guide on Replacing a Refrigerator Defrost Heater

By following these steps, you can keep your Whirlpool refrigerator running smoothly and your food fresh. Regularly checking and, if needed, replacing the flipper mullion can make a big difference in energy efficiency and overall cooling performance. 

It’s a simple DIY project that can save on repairs and lower energy bills. So next time you notice frost buildup or uneven cooling, you’ll know what to do!