The door latch was defective upon install.  Had to call in a technician to fix.  The Ultrafresh System did not work properly.  The technician had to adjust.  Specifically the fan did not work properly.  Had to do research to understand the Ultrafresh System as the owners manual that came with the machine.  I had to go online to find the owners manual.  The technician a week after the unit was installed informed me that the owners manual was online.  Also, I received a copy of the owners manual once I registered the unit.