AEG air fryer shows E4 and shuts down heating; may occur shortly after starting a cooking program.

Safety first: Disconnect from mains and allow the appliance to cool completely before cleaning or disassembly.

Steps to resolve E4:

• Check ventilation: Ensure the air fryer has at least 10 cm clearance on all sides and that rear/top vents are not blocked by walls, cabinets, or objects. Remove any obstructions.
• Clean grease and debris: Remove the basket and drawer. Clean the interior cavity, especially around the top heating area, with a soft brush and mild detergent. Grease buildup can trap heat and affect sensor readings.
• Inspect cooling fan operation: Power the unit briefly (with covers on) and listen for the internal fan. If the fan does not run or is noisy, unplug and access the fan from the rear or top. Check for obstructions (foil, food particles) and remove them. Spin the fan by hand; it should rotate freely.
• Check fan motor: If the fan is stiff or seized, the cooling fan motor may need replacement. Verify voltage at the fan connector when the unit is running (only if you are trained and can do this safely).
• Inspect thermal cut-out: Locate the thermal cut-out or thermostat on the heater housing. Check for signs of overheating or damage. Some are self-resetting; others are one-shot and must be replaced if open.
• Reassemble and test: After cleaning and any part replacement, reassemble the unit and run a low-temperature test cycle to confirm that E4 does not reappear.

Note: Persistent E4 after these checks may indicate a miscalibrated sensor or control board fault; professional diagnosis is recommended.