Air fryer displays E4 and will not heat or complete a cooking cycle.

Safety first: Disconnect power and let the unit cool completely. Internal safety devices may reset only after cooling.

Steps to clear E4:

• Allow full cool‑down: Leave the air fryer unplugged for at least 45–60 minutes to ensure any self‑resetting thermostat can cool and reset.
• Check for blockages: Confirm that the air intake and exhaust vents are not blocked by walls, cabinets, or objects. Remove any dust buildup with a soft brush or vacuum.
• Access safety thermostat: Remove the bottom or rear cover to locate the bimetal safety thermostat mounted on or near the heater housing. Some models use a small round thermostat with two terminals.
• Manual reset (if applicable): Some thermostats have a tiny reset button in the center. Press it gently with a non‑conductive tool until you feel a click. Not all models have this feature.
• Continuity test: With power disconnected, test the thermostat for continuity. If it remains open at room temperature and cannot be reset, replace it with a compatible Pro Breeze safety thermostat.
• Sensor placement: Ensure the NTC sensor is correctly clipped to its bracket and not touching the heating element directly, which can cause false overheat readings.
• Control board evaluation: If thermostat and sensor are good but E4 persists, the control PCB may be misinterpreting temperature data and should be replaced by a professional.

Warning: Do not tape down or bypass any thermostat or safety device. This is a serious fire hazard.