E12 appears and the machine reports a door or service panel open error.

Safety first: Unplug the coffee maker before adjusting the door or panel.

• Close door firmly: Open and close the Kenwood service door or front panel several times, pressing firmly until you hear a click. Ensure no cables or objects are trapped.
• Inspect latch: Check the plastic latch hook on the door and the corresponding catch on the body. If cracked or bent, the door may not engage the switch.
• Check for obstructions: Remove any coffee grounds or debris around the door frame that could prevent full closure.
• Test with gentle pressure: With the machine plugged in, gently press on the door while trying to start a cycle. If E12 disappears when pressing, the switch or latch is misaligned and may need adjustment or replacement.
• Persistent error: A faulty door microswitch or wiring harness will require internal access and should be repaired by a technician.