I have a luxaire 410a system with a heat pump. It's one year old. The problem is that it's not cooling sufficiently. I'm only getting 8 degrees temperature drop across acoil. I've checked the high and low side pressures off the compressor and they seem to be reading correctly. I then went into attic to examine acoil and when I did I noticed that only the last three coils had condensate dripping off them. The air blowing through these coils was extremely cold, while the ones with no condensate dripping off them had no cooling effect. Can can coils be plugged? Unit worked great last year and I never turned it on during the winter. It's done this since I've been using ac this summer. It was suggested that I add a little freon just to make sure the coolant wasn't low and I did this, but it didn't help.

May be a bad txv. Or could be this yr is just a lot hotter then last. Do you have a attic fan to get rid of heat in your attic?