We have a three compressor system in our home, one for our living room, one for the family room/kitchen, and one for the upstairs. The first two work great (including a 25 year old Carrier unit), the second system (made by Bryant) has been lacking over the past few summers and today I just got sick of it. When the system was first installed it worked great, blow heavy amount of air out of the ceiling vents and it was ice cold, took a short amount of time to reach target temperature. Now on a hot 85 degree day it will NEVER achieve target. Over the past few years it has been acting very strange. First thing I've noticed is that the hallway digital thermostat (Honeywell) "feels" off by a minimum of 4-5 degrees. When the temperature reads 72 degrees it is in reality at least 75+ in all of the rooms. I have a Honeywell tower fan in my personal room with a thermometer built in. If I am not running the window A/C AND the central A/C at the same time that thermometer typically reads 5+ degrees hotter than the hallway thermostat. I saw this first hand tonight when the thermostat read 71 degrees (not running) and the tower fan in my room read 77 degrees. I mean I wasn't expecting dead on accuracy but wow that is a rather large swing since the two are only about 15 feet apart. Don't even get me started on the master bath, that room feels like it is AT LEAST 7-10 degrees hotter than the thermostat claims. Keep in mind that putting my hand right into the ceiling vents feels like they are producing semi-cool air, not "WOW THAT'S COLD!" air like our other units. We've had a very popular HVAC company come out and look at the unit almost every summer, the only things that have ever been done to my recollection are finding leaks and topping up the coolant or recharging it. This always yields the same results, works better for a few days and then it's back to the warm air. So, why on EARTH would the digital thermostat read one temperature when in reality that ISN'T the temperature in the rooms? Where should I start trouble-shooting? I am a novice at this stuff and that is putting it politely. I know the main unit (condensor?) is in the attack with some kind of fan (sorry that is what I was told). The condensor is apparently clean and I see nothing blocking the A/C unit outside in terms of grass, debris, leaves, etc. I have some receipts I can pull out with detailed specs on the unit's status when it was just tested a couple months ago. I'm guessing we were told it "works fine" because it was barely 55 degrees outdoors and it was a late April morning around 8:30AM, not the best time to test a unit I'm sure. ANY help would be extremely appreciated with this. I will try to answer questions as best as I can. Only thing I won't do is crawl up into the attic...:NO NO NO:

My AC unit goes off and the screen of my thermostat goes blank. If I pull the outside fuse for 10 mins and put it back on the thermostat turns back on for a while but just says "waiting" for a while and then the whole thing turns off again. Any ideas? Thanks so much!