I am new to this forum and a homeowner who just had two brand new Carrier 3 ton central air systems installed. They have failed 5 times in the first 3 weeks of operation and the dealer suspects both units have bad TXV's? Has anyone else ever had this issue? Seems strange that both units would fail within days of each other. Carrier says that they have no replacement parts yet(too new to have parts?) but will have them soon? Also strange, considering I suspect they are making new ones? The units run non stop 24x7 and struggle to keep the house at 78-80 degrees? What else could be wrong? Any suggestions?