E20 displayed, refrigerator may not enter or exit defrost correctly, causing inconsistent cooling

Safety first: Unplug the refrigerator before accessing the evaporator area.

Steps:

• Verify correct sensor: If the evaporator sensor was recently replaced, confirm the part number matches the original Arctic specification.
• Check sensor mounting: Ensure the sensor is firmly clipped to the evaporator coil in the correct location, not hanging loose.
• Measure resistance: With the sensor at a known temperature (e.g., in ice water at 0°C / 32°F), measure resistance and compare to the expected value from service data. Replace if out of tolerance.
• Inspect wiring: Look for poor splices or extensions. Use proper crimp connectors and heat-shrink if repairs are needed.
• Control update: In rare cases, a control board firmware update or replacement may be required if sensors are correct but E20 persists.

Note: Incorrect sensor values can cause either heavy frost buildup or warm temperatures.