Step-by-Step Guide to Repair Your Refrigerator Flipper Mullion

If the flipper mullion on your Whirlpool-built French door refrigerator isn’t heating, you might notice issues such as condensation buildup or the mullion not flipping open and closed as it should. This component helps prevent moisture by staying slightly warm, which also ensures the fridge seals properly. Here’s a step-by-step guide to troubleshooting and fixing the issue.

Understanding the Role of the Flipper Mullion

The flipper mullion is a vertical strip located between the doors of a French-door refrigerator. Its primary functions are to prevent warm air from entering the fridge, reduce moisture buildup, and enhance the appliance’s energy efficiency. 

The mullion achieves this by staying slightly warm, which keeps condensation from forming on the seals. When it stops heating or moving as intended, the refrigerator may struggle to maintain an optimal temperature, leading to potential energy waste and compromised food storage conditions.

Safety First

When working on any appliance, it’s important to prioritize safety. Follow these guidelines:

1. Always unplug the appliance or turn off the circuit breaker before starting any repairs to eliminate the risk of electric shock.
2. Wear insulated work gloves to protect against sharp edges and debris. Safety glasses can help shield your eyes from dust or chemicals.
3. Work in a dry, well-lit space free of clutter. Ensure children and pets are kept away from the area.
4. Avoid excessive force when removing or handling components to prevent damage or injury.
5. If the appliance was recently in use, allow heating elements to cool completely before beginning any work.
6. iTake pictures or label wiring and connections before disconnecting anything to make reassembly easier.
7. If handling wires, use non-conductive tools or insulated gloves to avoid electrical shocks.
8. Refer to your refrigerator’s user manual for specific safety and installation instructions.

Tools and Materials You’ll Need

To troubleshoot or replace the flipper mullion, gather the following items:

• Multimeter
• Nut driver
• Flathead screwdriver

How to Fix a Refrigerator Mullion

Turn Off Power

1. Unplug the refrigerator or turn off the breaker to ensure the power is off.

Access the Mullion

1. Open the left-hand door and ensure the flipper mullion is in the open position.
2. Use a 1/4-inch nut driver to remove the mounting screw.
3. Push the mullion upward to disengage it from the upper and lower mounting tabs.
4. Push the mullion away from the door and remove the middle cover to expose the connector.
5. Disconnect the flipper mullion connector from the door.

Test the Mullion for Resistance

1. Set a multimeter to measure resistance (ohms).
2. Place the multimeter leads on the mullion terminals.
3. Check for a reading between 20 and 30 ohms.
4. If the reading is outside this range, replace the mullion. If it is within range, proceed to voltage testing.

Test Voltage

Warning: Testing live voltage involves risk of electric shock. Only proceed if confident in using a multimeter safely.

1. Plug the refrigerator back in.
2. Clear any “PO” or “PF” messages by pressing and holding the two leftmost buttons on the control panel.
3. Confirm the display flashes “01.” If it doesn’t, press the options button to toggle between “02” and “01.”
4. Use the 5th button from the left (marked with a plus sign) to advance to test 35.
5. Set the multimeter to measure DC voltage and place the leads on the door connector.
6. Check for a voltage reading between 12-15 volts DC.
7. If the voltage is incorrect, replace the user interface. If correct, proceed further.

Change the Heater Setting

1. Access test 34 by pressing the 4th button from the left (marked with a minus sign).
2. Change the heating mode from the default “01” (sensor-based) to “02” (continuous heating).
3. If moisture continues to form, inspect the door gaskets or internal door insulation.

Replace the Mullion

1. Unplug the refrigerator or turn off the breaker again to cut power.
2. Connect the mullion heater harness to the corresponding harness from the door.
3. Align the flipper mullion with the center cover and mounting tabs.
4. Slide the mullion into place, ensuring all mounting points are secure.
5. Reinstall the center cover screw with a 1/4-inch nut driver.

Restore Power and Verify Functionality

1. Plug the refrigerator back in or turn the breaker back on.
2. Confirm the flipper mullion is heating correctly and the refrigerator is running as expected.

And that’s it! Repairing your refrigerator’s flipper mullion might take a bit of time and patience, but it’s a rewarding DIY fix. With a little care and attention to detail, you’ll save yourself a service call and keep your fridge running smoothly. Remember, regular maintenance and quick action when issues arise can make a big difference in extending the life of your appliances.