Display shows E4 and the air fryer will not start or shuts down shortly after starting.

Safety: Unplug the unit and allow it to cool completely. Internal components near the heater can remain hot for a long time.

Steps to troubleshoot E4:

• External checks: Confirm the fryer is used on a hard, heat-resistant surface with adequate clearance. Remove any covers or foil that might block vents.
• Clean interior: Remove basket and pan. Clean heavy grease from the interior, especially around the heating element and top area. Use a damp cloth only when the unit is unplugged and cool; do not spray water directly.
• Access heater assembly: Turn the fryer upside down, remove the bottom cover screws, and carefully open the housing to access the heater and thermal safety devices.
• Locate thermal fuse / high-limit thermostat: On many Farberware models, a small cylindrical thermal fuse or disc-style thermostat is attached to or near the heating element bracket with two wires.
• Test continuity: With the unit unplugged, disconnect one lead and test the fuse/thermostat with a multimeter. It should read closed (near 0 ohms). If it reads open, it has tripped or failed and must be replaced.
• Replace the thermal fuse/thermostat: Install a compatible Farberware-rated thermal fuse or high-limit thermostat with the same temperature rating. Crimp or solder connections securely and insulate with high-temperature sleeving if required.
• Inspect for root cause: Check for blocked vents, non-running fan, or heavy grease that may have caused overheating. Correct these issues before reassembly.

Warning: Never bypass a thermal fuse or thermostat; doing so creates a serious fire hazard.