Bosch Microwave Error E-3: Automatic Door-Opening System Fault
On built-in Bosch microwaves with a motorized door-opening system, error E-3 means the electric mechanism that opens or closes the door failed to complete its travel correctly.
Common symptoms:
- E-3 appears on screen and the door won't open when the button is pressed
- A motor hum is audible but the door doesn't move
- The door stays ajar and the microwave won't start any program
Probable causes:
Food residue or a small object in the frame can prevent the mechanism from detecting a proper close and trigger the error.
With daily use, the lower hinge can lose a screw or loosen, causing the door to sag slightly and not seat properly.
The small electric motor or its plastic gears can wear out or break after thousands of openings.
Safe Inspection Checklist (Check off when completed):
Disconnect the appliance from the mains and wait about 10 minutes before plugging it back in; this resets the board and often clears the one-off error.
With the appliance unplugged, thoroughly clean the door frame and latch area with a damp cloth, removing any food or grease residue.
Check whether the door sags slightly downward or doesn't sit parallel to the cabinet frame, which would point to a hinge issue rather than the motor.
If E-3 persists after cleaning and resetting, and the door looks properly aligned, the opening system's motor or gear is likely faulty; given the complexity of the internal casing and the electrical risk, a technician specializing in Bosch microwaves is recommended.