I am hoping that some knowledgeable GTers can offer some helpful information and advice to me. Last month I had a 16 year old 3 ton Payne hvac system replaced that had a Freon leak in the evaporator coil and a blower was beginning to struggle. I decided to bite the bullet and replace the system before this one gave out. My heating/cooling square footage is 1470. It was replaced with an American Standard 3 ton system with a variable speed air handler. Immediately after installation, I began to notice that the system was short cycling running perhaps for 5-8 minutes and then restarting again within 4-8 minutes. The installer said this shouldn’t be happening, so he sent his men back out to relocate the thermostat which was originally on the wall above the air intake vents to a room further from the system. The system is still short cycling, particularly when the day is just beginning to heat up from about the hours of 9:30 am – noon. After that point, the run times increase slightly, but the restart times remain in the 4-6 minute range. By about 2:00, the system just runs and runs and runs until it begins to cool off outside. Around 5-6 pm, it will start the short cycling all over again until later in the evening when the house starts to loose heat in the attic. I also noticed the other day that there was condensation on my ceiling vents in a couple of the rooms. The installer is now telling me that I need insulation in the attic and on one section of the ducts up there (he never checked it prior to installation) and that he doesn’t know what else may be causing the problem unless the thermostat needs to be recalculated. I am keeping the house set at 77-78 degrees while I am home and 80-81 when I am away, and we are currently experiencing high 90’s to low 100 degree days. It’s been suggested by someone else in the hvac business that the system may be too large for the square footage and that is why it’s short cycling and getting the condensation. I am absolutely beside myself as this was a huge capital layout for me and I don’t know where to start. Any advice on how to proceed or how to approach the installer would be greatly appreciated. I listen to the system short cycling and all I can think about is the damage it is doing to the compressor and what it is doing to my utility bill. Thanks in advance, guys! Like I said, I am beside myself with this situation (mainly with worry and considering the $ that was involved) and any help you can give me that may rectify the situation will be more than greatly appreciated.