Display shows E20 and the refrigerator may not cool properly, with unusual compressor cycling.

Safety first: Unplug the refrigerator before accessing external sensors.

Locate ambient sensor: On some Insignia models, an ambient thermistor is mounted on the back or top of the cabinet to sense room temperature.

• Inspect sensor and wiring: Ensure the sensor is intact and wiring is not cut or pinched.
• Test thermistor: With the unit unplugged, disconnect the sensor and measure resistance at room temperature. Compare to expected NTC values. Open or shorted readings indicate failure.
• Replace sensor: Install a new Insignia-compatible ambient thermistor and secure it in the same location.
• Restore power and test: Plug the unit back in and monitor operation. The E20 code should clear if the sensor and wiring are correct.

Note: If the sensor is good but E20 persists, the main control board may be defective.