Microwave light, fan, and turntable run when the door is closed, even without pressing START.
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.
Possible Causes
How to Fix / Troubleshooting
Danger: A microwave that runs with the door closed but without a command is unsafe. Unplug it immediately and do not use until repaired.
Inspection (advanced):
- Remove the cabinet and inspect the door switch wiring to ensure it matches the wiring diagram for your Commercial Chef model.
- Test each door switch for proper operation; replace any that are stuck closed.
- If switches are correct, the control board relay may be welded closed and will need replacement.
This condition should be corrected by a professional to ensure safe operation and proper shielding.
Repair Difficulty
Required Part
We may earn a commission from links on this page.