Report "I just replaced a dead Broan motor with BP-27, the old unit is model#669. I installed it andd it works fine, except it seem to be blowing air into the bathroom instead of pulling out the air. It was very dirty and I cleaned the housing and mounting plate, I even removed the damper. Is there anything I can do to fix this problem. Could there be a blockage in the exhaust line and how would I be able to clean it out. We live in a 2 story apartment and live in a lower unit, where there are no crawl spaces or access to the line"