Air fryer will not start; display shows E1 immediately after power-on or when pressing START.

Safety first: Unplug the Klarstein air fryer from the mains and let it cool completely before opening the housing. Capacitors on the control board can retain charge.

Steps to check and correct:

• 1. Access the top housing: Remove the basket and pan. Turn the unit upside down on a soft cloth. Remove the perimeter screws holding the top or bottom cover (varies by Klarstein model). Carefully separate the housing without pulling on wires.
• 2. Locate the NTC sensor: The cabinet temperature sensor is usually a small metal probe or bead-type sensor clipped near the heating element or in the air channel, connected by two thin wires to the control PCB.
• 3. Inspect wiring and connector: Check that the sensor plug is fully seated on the control board. Look for broken, pinched, or burned wires. If a wire is broken at the probe, the sensor must be replaced.
• 4. Test continuity (optional but recommended): Using a multimeter set to resistance, measure across the two sensor leads. A typical NTC will show several kΩ at room temperature. If the meter reads OL (open), the sensor is defective.
• 5. Reseat or replace: Reseat the connector firmly. If the sensor is open or physically damaged, replace it with a compatible Klarstein NTC temperature sensor assembly. Route the new sensor along the original path and secure it with clips or high-temperature tape, keeping it away from moving fan blades.
• 6. Inspect control board input: Examine the control PCB for burned or cracked solder joints at the sensor connector. Reflow solder if you are qualified; otherwise, replace the control board.
• 7. Reassemble and test: Refit the housing, ensuring no wires are pinched. Plug in the fryer and power on. If E1 is cleared and the unit heats normally, the repair is successful.

Warning: Do not bypass or short the sensor to defeat the error; this can cause overheating and fire risk.