Display shows E3 and the unit beeps and stops heating shortly after starting a cook cycle.

Safety first: Unplug the air fryer and allow it to cool for at least 30–45 minutes. Overheat conditions can be a fire risk.

• Step 1 – Check placement and ventilation: Ensure the Cosori air fryer is on a hard, heat-resistant surface with at least 5 inches (12 cm) clearance on all sides and top. Do not operate under cabinets or in enclosed spaces.
• Step 2 – Inspect and clean vents: Examine the rear and bottom vents for dust, grease, or obstructions. Use a soft brush or vacuum to clear vents. Clean the interior top area around the heating element with a damp cloth once cool.
• Step 3 – Verify fan operation: Start a cook cycle and listen for the internal fan. If the fan does not run or sounds weak, unplug the unit and access the fan assembly from the rear or top (model dependent). Check for food debris blocking the fan blades.
• Step 4 – Inspect fan motor and wiring: With the unit unplugged, spin the fan blade by hand; it should rotate freely. If stiff or seized, the convection fan motor may be failing and should be replaced. Check the fan motor connector at the control board for a secure fit.
• Step 5 – Check thermal fuse/thermostat (advanced): Many Cosori models include a thermal cutoff or thermostat near the heating element. If open, the unit may overheat locally or shut down erratically. Test continuity with a multimeter and replace if open.
• Step 6 – Control board: If ventilation is clear, fan runs properly, and safety devices test good, the main control PCB may be mismanaging temperature and should be replaced.
• Stop using if burning smell persists: If you notice persistent burning smells or visible smoke from the housing, discontinue use and contact Cosori or a technician.