They came back this morning with their "expert", who is baffled and must call the factory (Trane) for help. The factory, of course, is closed over the weekend. It is incredibly frustrating, and hot. I hate feeling taken advantage of, and that's exactly what I am feeling right now. One of the primary reasons I went with this company was that they promised to have the system installed (AND RUNNING) on Friday! My only leverage is that I have not paid them a dime.