Installation was a nightmare when we put in a new furnace and AC back in mid-2008. We provided detailed requirements which were never relayed to the contractors; the job was sloppily done, with caulking smeared over the new furnace and pipes extending too far into our mutual driveway. To add insult to injury, although they didn't bother to invoice us, they started making threatening calls about payment starting on the day of installation. It's a couple years later now, and although our AC is on a 10-year warranty, they now refuse to honor it, claiming (a) the company has changed hands, and (b) the detailed invoice they eventually issued us isn't a valid legal document for warranty purposes and what we actually need is a letter from the manufacturer. The person I just spoke with on the telephone says she's fielded dozens of calls from people with the same complaint.