Ft Worth Texas: I too decided that it was time to replace the worn out system in my 20 year home, and purchased two three ton Lennox xp19 systems with matching hardware. After the installation, the contractor has been to my home every month thereafter, and has eventually decided that he doesn't want to support the thing anymore. HOWEVER, reading the instructions guide detailing installation of the unit, and knowing a little about installing and maintaining heat pumps, I found several instances in documentation where the contractor simply did not follow instructions. For example, the XP19 installation guide (document revision 12/09), on page 12 clearly indicates that after brazing lines, nitrogen should be used to flush the lines. This was not done. Worse, the contractor did not evacuate the lines (as detailed on pages 17 and 18) before they charged the unit. Also, throughout the installation guide, there are little notes spread around here-and-there about how "If <this process> is not verified/performed, the compressor will fail in the future." (see page 24). And then add to this that the contractor allowed the lubrication to escape from the condensor unit, too. I saw them do it! And when I asked them if they were going to replace that, they said it was not important. I know the lubricant is important, but I have not been able to find the quote. I think Lennox makes a great product. But I seriously question the competency of the installers. Day loborers (ie illegals) did my installation, so I strongly suspect they were not Lennox certified… Blame the contractor doing the install.