Display shows E4 and the compressor or cooling module does not start or shuts off quickly.

Safety: Unplug the Ivation wine cooler. Allow any ice buildup to melt before working near the evaporator to avoid damage.

Troubleshooting steps:

• Inspect for heavy frost: Remove interior shelves and rear panel. If the evaporator is encased in ice, allow it to fully defrost with the unit unplugged for several hours. After defrosting, plug in and check if E4 returns.
• Locate the defrost/over-temp sensor: This is usually a small sensor clipped to the evaporator tubing or fins, separate from the main evaporator thermistor.
• Check wiring and mounting: Ensure the sensor is firmly attached to the tubing/fins and that its wires are intact and not corroded. Reseat the connector at the control board.
• Test the sensor: Use a multimeter to measure resistance at room temperature and compare to Ivation’s specifications. An open or shorted sensor will trigger E4.
• Replace if faulty: Install a new Ivation defrost / over-temperature sensor, clip it securely to the evaporator, and reconnect the harness.
• Reassemble and test: Reinstall panels, restore power, and verify that E4 is cleared and the compressor runs normally.

Note: If the sensor is good and wiring is intact, the main control board may be defective and should be evaluated by a professional.