I am an industrial A/C tech. and just moved into a house we had built.Turned on the heat for the first time last night.It is a dual zone system with gas heat.The downstairs was 66F and the upstairs was 75F both T-stats are set at 66F.I checked out the system after calling the installing contractor and them telling me they could get to me in about a week.What I found was the damper for the upstairs was closed but air still came out of up stairs vents. So I took the damper out and found the damper is 1 1/4 inches short lengthwise and a half inch shorter on height than my ductwork. My question is shouldn't this damper seal off better or is it supposed to have some bypass.I should also mention this metal damper and motor are mounted in ductboard with no support. Will the ductwork sag and lose its shape in the future? Sorry for the long post.Any info is greatlt appreciated.