Oster digital air fryer will not start a cooking cycle and displays error code E1 on the control panel.

Safety first: Unplug the air fryer and let it cool completely before opening any panels. Never work on the unit while it is connected to power.

Error E1 on many Oster air fryers indicates the temperature sensor (NTC) is not being detected by the control board.

• Power reset: Unplug the fryer for 10 minutes, then plug back in and try again. Sometimes a transient fault clears.
• Check for obvious damage: Inspect the power cord and exterior for burn marks or melted plastic. If present, stop and contact a technician.
• Access the sensor: Remove the basket and drawer. From the back or bottom (depending on model), remove the screws securing the rear/bottom cover to access the heater cavity. The NTC sensor is usually a small metal probe or button clipped near the heating element with two thin wires leading to the control board.
• Inspect the harness: Verify the sensor plug is firmly seated on the main control board. Look for broken, pinched, or burned wires. Reseat the connector.
• Test continuity (for advanced DIYers): Using a multimeter set to resistance, measure across the sensor leads. A typical NTC will show some resistance (e.g., 50–200 kΩ at room temperature). If it reads open (OL), the sensor is bad.
• Replace the sensor: If the sensor is open or physically damaged, remove its mounting clip or screw, disconnect it from the board, and install an OEM Oster-compatible temperature sensor. Route the wires away from the heating element and sharp edges.
• Control board check: If a known-good sensor is installed and wiring is intact but E1 persists, the main control board sensor input is likely faulty and the board must be replaced.

If you are not comfortable opening the appliance or using a meter, contact a qualified small-appliance technician.