Air fryer will not start and displays E1 on the control panel.

Safety first: Unplug the air fryer and let it cool completely before opening any panels. Never work on a live appliance.

• Power reset: Unplug the unit for 5–10 minutes, then plug back in and try again. Sometimes E1 is a transient sensor read error.
• Check basket and door: Make sure the basket is fully inserted and the door is completely closed; some Chefman models will not read temperature if the safety switch is open.
• Inspect sensor wiring: Remove the outer housing (usually Phillips screws on the back/bottom). Locate the thin, insulated wires running from the heating cavity to the control board (this is the NTC sensor harness). Check for burnt, cut, or disconnected wires and reseat any loose connectors.
• Check sensor resistance: With a multimeter set to kΩ, measure across the NTC sensor leads. At room temperature, most Chefman NTCs read between 50kΩ–100kΩ. If the meter shows OL (open) or 0Ω, the sensor is defective and should be replaced.
• Replace faulty parts: If the sensor is open or the harness is damaged, replace the temperature sensor assembly. If the sensor tests good but E1 persists, the control PCB sensor input is likely faulty and the main control board should be replaced.

If you are not comfortable opening the unit or using a multimeter, contact a qualified appliance technician.