I purchased a house two years ago during August. I do not recall any issues regarding ac in the upstairs at that time. The following year and this year the AC upstairs doesn't work. If it is 85 degrees outside I can barely get it to 82 degrees upstairs. The other two zones on the main floor work fine. The only change that I am aware of was that the outside condensor units were replaced soon after I moved in.
Also, the room at the far end of upstairs doesn't get enough heat in the winter.
I have had three HVAC contractors over, and each one wants to sell me new units, although none can explain why there are both heat and cooling issues (the cooling issues have been explained as either because of mismatch with the older indoor units) or lack of air flow upstairs (which of course wouldn't change unless large leaks in the ducts occurred for no reason).
I need to find a contractor in the Westchester NY area that can determine the real cause of these problems, and not just try and sell me a new unit, as there is no gaurantee that a new unit will work any better.