The glue behind the keypad loosened and the keypad slowly began slipping down out of place over several months. Finally, because of the movement, it warped which resulted in one of the keys being stuck. That is what gave the F12 error code. The fix was easy. I removed the control panel and then peeled off the keypad. The keypad itself then has two layers (1), the flexible circuit panel, and (2) the outward facing display. I separated the display from the circuit panel and put the new one in place. It is basically a sticker. Buttoned everything back up and it’s working perfectly. To get to the control panel. Remove the upper back panel (6 screws), unplug the panel plugs (they won’t get mixed up, they only go back in one way), and then there are 4 screws for the control panel. When you reconnect the switch pad to the control panel, you’ll need to pull up the plastic locking mechanism on the plug insert to open it. Then push it down again to lock the plug in. Of course, kill the power to the unit first!