Microwave shows E3 and does not heat or stops mid-cycle

Critical safety warning: Microwaves contain high-voltage components that can cause severe injury or death. Always unplug the unit. Do not discharge or handle the high-voltage capacitor or magnetron unless you are a trained technician.

• Check external airflow: Ensure the rear and top vents are clear of obstructions. Clean grease and dust from vent grilles.
• Listen for fan operation: During a short test run (with a cup of water inside), listen for the internal cooling fan. If the fan is not running but the turntable and light work, the fan motor or its wiring may be faulty. Stop using the microwave until repaired.
• Allow full cool-down: If the microwave was used for long periods, let it cool for at least 1 hour, then try again. A tripped thermal cut-out may reset when cooled (some are auto-reset, others are one-time fuses).
• Internal inspection (advanced): With the cover removed (unplugged), locate the magnetron thermal cut-out (small round thermostat clipped to the magnetron or waveguide). Check for burned wires or loose connectors.
• Replace failed thermal fuse or fan: If the thermal cut-out is open (tested with a meter) or the fan motor is seized, replace with Haier-specified parts. Do not bypass any safety thermostat.
• Persistent E3: May indicate a failing magnetron or control board; professional diagnosis is recommended.