Air fryer shows E4 and shuts down shortly after starting; sometimes accompanied by a hot smell or very rapid heating.

Safety first: Unplug the unit and let it cool completely. Do not attempt to reset or bypass safety devices.

Steps to address E4:

• Check placement and ventilation: Ensure the air fryer is not pushed against a wall or under low cabinets. Clear all vents of obstructions.
• Clean interior and vents: Remove the basket and drawer. Clean the interior, especially the top area around the heater and fan guard. Use a soft brush to remove baked-on grease from vents.
• Inspect cooling fan: With the unit unplugged, look through the top or rear vents and gently spin the fan blades with a plastic stick. They should rotate freely without scraping.
• Access heater assembly: Remove the outer housing to reach the heater, fan, and thermal fuse. The thermal fuse is usually a small cylindrical component clipped to the heater housing with two leads.
• Test thermal fuse: Use a multimeter to check continuity. If open, it has blown due to overheating and must be replaced with an identical Beko thermal fuse (same temperature rating).
• Investigate cause of overheating: Before replacing the fuse, confirm the fan motor runs properly (see fan-related entries) and that vents are clear. Replacing a fuse without fixing the root cause can lead to repeat failure.
• Reassemble carefully: After replacing the thermal fuse and verifying airflow, reassemble the housing and test with a short cycle while monitoring for abnormal heat or smells.

Warning: Never bypass a thermal fuse; doing so creates a serious fire risk.