LG Microwave DOOR Error Code — What It Means
The DOOR error on your LG microwave indicates the control board is not receiving a valid signal that the door is closed and latched. The microwave relies on a series of door interlock switches that must all confirm the door is secure before allowing the unit to start. When any part of this safety system fails to report proper closure, the control locks out operation and displays DOOR.
This fault is most often triggered by a physical obstruction preventing full closure, a door that has not been pushed firmly shut, or a failed door interlock switch inside the cabinet. LG specifies that if the error persists after basic checks, the unit requires service for proper diagnosis.
Common Causes
- Packing material or debris at the door edge Foam, plastic wrap, food particles, or other foreign material along the door gasket or latch area physically prevents the door from seating fully against the cabinet frame.
- Door not closed firmly or latch not engaged The door may appear shut but the internal latch hook has not traveled far enough to actuate all the interlock switches, leaving the control without a complete closed signal.
- Cooking rack installed out of position A metal rack that is not seated correctly or is the wrong size can protrude beyond the cavity and hold the door slightly open, blocking the latch mechanism.
- Failed or misaligned door interlock switch One or more of the mechanical switches that detect door closure has failed internally, become stuck, or shifted out of alignment so the latch actuator no longer closes the contacts.
- Broken latch hook or latch receiver The plastic or metal hook that extends from the door, or the corresponding receiver bracket on the cabinet, has cracked or bent so the latch cannot engage the switches with sufficient travel.
- Control board input fault If all door hardware is intact and switches test good, the main control board may have a failed input circuit that cannot read the interlock signals correctly.
Step-by-Step Fix
- Unplug the microwave from the wall outlet or switch off the dedicated circuit breaker to remove all power before inspecting the door area.
- Inspect the door opening and latch area for packing material, food debris, bent metal tabs, or any obstruction along the gasket and strike plate, then remove any foreign material and wipe the surfaces clean.
- Check the cooking rack position if your model uses one, ensuring it sits fully inside the cavity guides and does not protrude past the door plane when the door closes.
- Close the door firmly and listen for a distinct mechanical click as the latch engages, then verify the door sits flush and square against the cabinet frame with no visible gaps.
- Access the interlock switch assembly by removing the outer cabinet panels (consult your service manual for fastener locations), locate the door switches mounted near the latch receiver, and inspect the switch bracket and actuator arm for cracks, misalignment, or broken mounting tabs.
- Test each door switch with a multimeter set to continuity mode, manually actuating the switch lever to confirm the contacts close and open cleanly, and replace any switch that shows open contacts when pressed or intermittent readings.
- Reassemble the cabinet, restore power, close the door, and press Start to verify the microwave runs normally without displaying DOOR, confirming that the interlock system now reports proper closure to the control board.
Parts Often Needed
| Part | Notes |
|---|---|
| Door interlock switch | Amazon | Primary or secondary latch-position switch. Match your model number and confirm switch type (normally open or normally closed) before ordering. |
| Door latch assembly | Amazon | Complete hook and actuator mechanism. Replace if the latch hook is cracked, bent, or no longer engages the receiver bracket with full travel. |
| Door latch receiver bracket | Amazon | Cabinet-mounted strike plate and switch holder. Required if the mounting tabs are broken or the alignment bosses are stripped. |
| Main control board | Amazon | Only after confirming all mechanical components and switches test good. Verify part number from the existing board label. |
When to Call a Pro
LG directs that service is required for proper diagnosis if the DOOR error remains after you have checked for obstructions and confirmed the door closes firmly. Call a qualified appliance technician if you are uncomfortable working inside the cabinet with the outer panels removed, if you do not have a multimeter to test switch continuity, or if replacing interlock switches and latch hardware does not clear the fault. High-voltage components are present even when the magnetron is not running, and misdiagnosis of the interlock system can create a safety hazard. A technician will also have access to the full wiring diagram and can isolate whether the fault lies in the door hardware or in the control board input circuit.