Display shows E4 and the freezer or refrigerator section ices up around the evaporator, with poor cooling and fan noise.

Safety First: Unplug the refrigerator and be prepared for water from melting ice. Keep towels handy.

Steps:

• Access evaporator area: Remove freezer contents and the rear interior panel to expose the evaporator coil.
• Locate defrost sensor: The defrost thermistor is usually clipped to the evaporator tubing near the top or middle of the coil, often wrapped in foil or insulation.
• Check mounting and wiring: Ensure the sensor is firmly attached to the coil and that its wires are not cut, pinched, or corroded.
• Defrost the coil: Use a hair dryer on low to melt heavy frost/ice from the evaporator and sensor. Do not use sharp tools.
• Measure resistance: With the unit unplugged, disconnect the thermistor and measure resistance. At freezing temperatures, resistance should be higher than at room temperature. A reading of 0 ohms or infinite indicates failure.
• Replace if faulty: Install a new Midea defrost thermistor, clip it securely to the evaporator, and reconnect the harness.
• Reassemble and test: Reinstall the evaporator cover, restore power, and monitor for proper defrost cycles over 24–48 hours.