air fryer shuts off by itself mid-cycle with a burning smell, no error code

Diagnosis

The Cosori Pro III 5.8QT utilizes a thermal fuse and a high-limit thermostat designed to kill power to the heating element and fan immediately if internal temperatures exceed a safe threshold. When the unit shuts off mid-cycle without an error code (like E1 or E2), it is almost always a "hard trip" of the overheat protection circuit. This occurs because the internal airflow is restricted, preventing the heat from being dissipated away from the heating element and the electronic control board. The burning smell you are experiencing is likely "pyrolysis"—the chemical decomposition of old grease, oil droplets, and food debris that have migrated upward into the heating element chamber over time. As these residues bake onto the element, they create a layer of carbonized sludge that traps heat and smokes. Once the internal sensor detects that the air isn't moving fast enough to cool the element, it cuts power to prevent a potential electrical fire. You can confirm this by noticing that the fan stops abruptly and the digital display may either go blank or freeze before the unit completely dies.

How to Fix It

To resolve this, you must perform a deep internal decontamination of the heating chamber to restore proper airflow and remove combustible residues.

1. Disconnect the power cord from the wall outlet and allow the unit to cool for a minimum of 60 minutes. Attempting this while the unit is warm can cause severe burns or damage the non-stick coating.
2. Remove the air fryer basket and the inner non-stick cooking pot. Set them aside for a separate deep clean.
3. Position the main housing upside down over a large trash bin or a cardboard box to catch falling debris.
4. Using a can of high-pressure compressed air (specifically the type used for electronics), insert the straw nozzle into the top vents and the gaps around the heating element. Blast the air in short, 2-second bursts to dislodge carbonized food particles and grease clumps from the heating coil.
5. Take a long-reach microfiber cloth or a flexible bottle brush dipped in a mixture of warm water and a grease-cutting dish soap. Gently wipe the perimeter of the heating element (the coil) and the interior walls of the upper chamber. Avoid scrubbing the coil too aggressively to prevent bending the metal.
6. Use a dry paper towel to wipe away any remaining moisture from the interior housing.
7. Plug the unit back in and run a "Burn-off Cycle": Set the temperature to 400°F for 10 minutes while empty. This will incinerate any remaining loosened residue. Expect a slight smell for the first 5 minutes; this is normal during the recovery process.

If That Didn't Work

• Check the Air Intake Vents: Inspect the rear of the unit where the intake vents are located. If the air fryer is placed too close to a wall or under a cabinet, it cannot pull in cool air, causing the internal temp to spike. Ensure there is at least 5 inches of clear space on all sides.
• Inspect the Fan Blade: Use a flashlight to look through the top grill. If you see a visible obstruction (like a piece of parchment paper or a stray vegetable scrap) jammed in the fan blades, use a pair of long tweezers to carefully remove it. If the fan cannot spin at full RPM, the unit will overheat in minutes.
• Test with a Different Circuit: If the unit shuts off specifically when using high temperatures (400°F+), you may be tripping a GFCI outlet or a circuit breaker in your home. Plug the Cosori into a different circuit on a separate wall to rule out external power failure.
• Factory Reset: Though rare for overheat issues, a glitch in the control board can cause premature shutdowns. Unplug the unit for 30 minutes to allow the capacitors to fully discharge, then restart.

Heads Up

• Avoid Over-lining: Never place parchment paper or foil directly on the bottom of the basket without food on top to weigh it down. The air suction can pull the paper into the heating element, causing an immediate overheat trip and a potential fire.
• Monthly Degreasing: Every 30 uses, perform a "dry blow" with compressed air to prevent grease buildup in the upper chamber, as the Cosori Pro III does not have a removable heating element.
• Avoid "Wet" Cleaning Internals: Never spray cleaning chemicals or water directly into the top vents. This can short the control board or cause the heating element to rust, leading to permanent failure.
• Scent Management: If the burning smell persists after cleaning, avoid using high-fat sprays (like aerosol oils) which atomize and coat the internal heating coils more aggressively than oil brushes.