Refrigerator display shows E1 and fresh food section temperature is inaccurate or fluctuates.

Safety first: Disconnect power before accessing internal panels.

Locate the refrigerator thermistor: On Insignia refrigerators, the fresh food thermistor is typically behind a small plastic cover on the rear interior wall of the refrigerator compartment or clipped to the evaporator cover.

• Visual inspection: Remove the thermistor cover. Check that the sensor bulb is intact and the wires are not cut, pinched, or corroded.
• Check connection: Follow the thermistor wires to the connector. Ensure the connector is fully seated and not oxidized. Reseat it firmly.
• Basic resistance check (if you have a multimeter): With the refrigerator unplugged, disconnect the thermistor and measure resistance across its leads. At room temperature (around 77°F / 25°C), most Insignia NTC thermistors read roughly 5k–10k ohms. A reading of 0 ohms (short) or infinite (open) indicates a bad sensor.
• Replace thermistor if faulty: If the sensor is open/shorted or physically damaged, replace it with the correct Insignia refrigerator compartment thermistor. Route the new sensor wiring along the original path and secure it with clips or tape to avoid contact with moving parts or sharp edges.
• Reset and test: Restore power and allow several hours for temperatures to stabilize. Confirm that the E1 code clears and that the refrigerator maintains the set temperature.

Note: If a known-good thermistor does not clear the E1 code, the main control board may have a failed sensor input circuit and will need replacement.