Display shows E4 and the air fryer will not start or shuts down quickly.

Safety first: Unplug the unit and let it cool. Do not operate with covers removed.

Steps:

• Power reset: Unplug for 10 minutes, then reconnect and test. If E4 appears immediately, continue.
• Access control area: Remove the top or rear cover (depending on model) to access the control board. Keep track of screw locations.
• Identify sensors: Many PowerXL models use a primary NTC near the heater and a secondary sensor near the air inlet or control area. Trace thin two-wire harnesses from the board to locate both.
• Check connectors: Gently unplug and replug each sensor connector on the control board. Inspect for bent pins, corrosion, or loose fit.
• Inspect harness routing: Ensure sensor wires are not pinched between plastic housings or touching sharp metal edges. Reroute and secure with cable ties if needed.
• Test resistance (advanced): Measure resistance of the suspected ambient sensor at room temperature. Compare to the primary NTC; they should be in a similar range. A reading of OL or 0Ω indicates a failed sensor.
• Reassemble and test: After reseating or replacing the sensor, reassemble the housing and test for E4.

Note: If both sensors test good but E4 persists, the control board is likely defective and should be replaced as a complete assembly.