NuAir Windows Won't Close All the Way

It looks like your window's Top Sash Guides broke. The Top Sash Guides are those nylon pieces in the top corners of the window sash. They hold the channel balances in place--the channel balances are spring-loaded metal channels that regulate the opening and closing of the window. Due to age and sun exposure, the Top Sash Guides can break; when they do, the channel balances shoot past the sash and into the top corners of the window jamb.

Watch the video below that shows how to remove and replace Top Sash Guides. NuAir windows have been known to use either our 18-009 or 18-178 pair, but the only way to possibly know is to compare an undamaged guide to confirm.