I bought a new house new build in May 2016. The HVAC air ducts continuously blow air or heat into the stairwells and not the living areas. I have brought this issue to the home builder and HVAC company that installed the unit and they keep informing me there is nothing that can repair this. Well, I don't believe that. So I am reaching out to This Old House for advice on this matter. Are there any other resolutions to stop the air or heat from blowing directly into the stairwell and blow into the living areas?