I've got a question for you. I live in a duplex (2 stories w/ a basement) with how cold it's been we turned our heat on. The main level is nice and warm like i want it, but for some reason the upper level is a lot colder. At first i thought it was that air wasn't getting up stairs well (had the same problem in summer w/ the AC) so I closed some of the vents down stairs, still now help. There's not much I can do as I rent, but any ideas on what could be wrong??? Thanks, Travis