H2 appears and the unit stops heating mid-cycle.

Safety first: Unplug and allow the air fryer to cool completely before cleaning or disassembly.

• Clear vents: Inspect rear and top vents for obstructions. Clean dust and grease with a soft brush and mild detergent (do not let water enter electrical areas).
• Deep clean interior: Remove baked-on grease from the heating element guard, fan shroud, and upper cavity using a non-abrasive cleaner and soft cloth. Heavy grease can trap heat.
• Check fan speed: During operation, listen for the fan. If it sounds slow or labored, inspect and clean the fan blades and motor. Replace the fan motor if it does not reach full speed.
• Inspect high-limit thermostat: Access the thermostat on the heater bracket. If it is a resettable type with a small button, press to reset after cooling. If it trips frequently, consider replacing it with the correct Ultima Cosa-rated part.

Persistent H2 errors after cleaning and fan repair may indicate a miscalibrated control board or incorrect thermostat and should be evaluated by a technician.