May never have opened. Bought the home new. Just replace louvered vent on outside of house. When I ran the fan to make sure new vent worked properly it was almost as if it was being sucked shut. Could the original install have wired or mounted the motor wrong so that it is pulling in air rather than exhausting?
No, the motor runs so it is wired correctly, as it is an AC motor.
I would suggest pulling off grill and with unit off, check to see if damper will open with a small stick or pencil. Most often problem is blockage by debris or the like.
If it does open when gently pushed open. Using a flashlight and staying clear of the fan, observe flapper door while someone else turns on fan, to see if it opens.
As it is in a new home, the outlet of the fan should go into some ducting, routing the moist air out of the attic area. If this ducting is collapsed or incorrectly installed, you will have the same kind of problem you are describing.
Date published: 2016-10-29