E4
LG Magnetron Overheat or Thermal Cutout Trip

Microwave shows E4 and may shut down during cooking, especially at high power.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Blocked air vents, Failed cooling fan motor, Dust-clogged air passages, Weak or failing magnetron drawing excessive current

How to Fix / Troubleshooting

Safety warning: Unplug the microwave and let it cool. Do not attempt to access internal components.

Steps:

  • Check external vents: Make sure the rear, side, and top vents are clear. Remove any items stored on top of the microwave that may block airflow.
  • Clean grease filters: On over-the-range models, remove and clean the bottom grease filters. Dirty filters restrict airflow and can cause overheating.
  • Listen for fan operation: During a short TIME COOK test, listen for the internal cooling fan. If you do not hear airflow from the side/top vents, unplug the unit and arrange service.

If E4 recurs even with good airflow and a working fan, the magnetron or thermal cutouts may be failing. These are high-voltage components and must be serviced by a qualified technician.

Advertisements

Repair Difficulty

Professional Required 5/5

Required Part

Cooling Fan Motor or Magnetron Assembly
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements