I had a 17+ year old Coleman system. The condensor blower motor went and shortly thereafter the compressor went. Since my air handler is in the attic, the serviceman recommended a "dry" system (XB13: 2TTB3042A) which would allow me to continue using my original AH with the R22. While it worked for about a week, it started blowing room temperature air. Installer returned, claimed he checked the charge, capacitors, etc and everything was fine. He went into the attic and claimed that the AH had an older piston metering valve and needed a TEV because the above SEER 13 unit was not compatible with the piston metering device. He claimed it would work for a while but then would eventually freeze up and not provide any cooling at all. He would not guarantee that he would be able to install a compatible TEV. He suggested getting a new air handler to work with the R-22. So I'm asking:
1. Is his assessment of the problem reasonable?
2. If I end up having to replace the AH shouldn't I swap out the above condensing unit and go with a complete R-41 unit?
3. Should the installer had known about the metering problem prior to giving me the equivalent of a large paperweight?