I believe ours is mounted in the vertical configuration and my son thinks the UPM board is on the bottom and very difficult to get at. I can't really tell from the manual where it is, but you'd think there would just be a removal panel on one of the sides you could get at. Bosch Water Source Heat Pump Model Serial: 2940-457-000001-7735019699 SM060-1CFC-SLBATA-EHGXXXXXD7XXXX8XXXXSBA Each unit is provided with a factory installed Unit Protection Module that controls the compressor operation and monitors the safety controls that protect the unit. Screen shot from a Bosch youtube video: