If anyone can help me here I would appreciate it! This is the same problem I had last year. As soon as the temp. outside gets about 88-90 degress and then definately above 90 I have been having problems!!!!!!!!!! what happens is that the unit cycles on about 9:00 am and runs to about 10:30 pm. I have it set on 72 and the in room temp. rises to about 77 or 78 and the spends the night catching up and eventually cycling off about 10:30 or 11:00 pm. First I will rule out all the obvious. Nothing has changed, no new roof, no trees have been cut down, etc. I have had technician after technician come by and they all hook the gauges and the unit is not over or under charged, it seems to be running perfect. inside the temperature diferential from the closet register to the return is good. all filters are clean and the air flow is good, also does not need a new thermostat.
any help will be greatly appreciated!