Our upstairs, especially on the coldest days, was 10-15 degrees hotter than the downstairs. We tried everything from closing vents to getting new insulation but nothing really mattered. So I used my American Home Shield warranty to hopefully investigate and they put me in touch with ARS. The one thing I didn't like is that my appointment window was from 12-6. However, I asked them to give me the last appointment so the repair person didn't come until after 6 which was nice. They were supposed to call when they were 30-45 minutes away but he just showed up. He told me that the dampers that controlled the heat were probably broken but didn't seem to do too much investigation for other possible reasons. He didn't know if the warranty would cover it or how much ARS would charge otherwise but would call me before lunch the next day. He did not call so I called at 4. He said he would call back in 10 minutes but it was closer to an hour. The warranty would not cover it so it would be $244. After talking about it with my wife, we decided to try. I made an appointment for the next day. At 5:30 I called to see where he was and was told he would be there shortly. At 6:30, ARS called to say that he had forgotten to put the equipment on the truck so would have to reschedule. That made me upset. First of all, she didn't appologize. Second, I was off that day and any other time would be inconvienent for me. Up to that point, everyone I talked to at ARS couldn't be nicer. So he came the following day but didn't apologize. (Didn't get a call either that he was on the way over.) But he replaced the part relatively quickly. After 5 days, it seems like the job worked. Very little air is coming upstairs (what we wanted). So instead of 10-15 degrees warmer, usually 6-7. Hoping it is a long-term fix.