Nu Air Windows

Hello,

I have 7 Nu Air windows, all with the same ~60.5" height, four with a 51" width, two with a 35.5" width and one with a 34.5". They pretty much all have an issue with the locks not being able to close cleanly or not at all. The wider windows have two locks and only one will lock on each.

I took pictures of one of the 51" wide windows showing the bottom sash removed from the frame and of the bottom right channel balance. The string on the bottom right channel balance was broken when I took the sash out, which is probably why it won't stay open on its own. The top left channel balance string looked fine.
The picture of the top channel balance inside the frame hangs out quite a bit when the sash is installed and when the top plastic holder isn't holding it in, should it hang out that much?
The channel balance width is a little over 1/2". The two pictures of the top and bottom right side of the sash are identical to the left side. There is a marking on the channel balance that says "29 5 LW CMC 1". The length of the balance is about 31" including the plastic pieces.

I hope this is enough information for you to assist me in getting the parts I need to get my windows working properly so they lock and are sealed. If you need anything else, please let me know and I look forward to hearing from you.

Thank you,
Steven

Hi Bob,

Thank you for the response.

The windows are all hard to open but they all stay open except for the one I mentioned. The locks and the windows sealing properly are my main issue since I live in Florida and want to keep the heat out. It does look like some of them are missing the sash guides on the bottom after further inspection.
I measured the bottom shoe and it is 1" so the S380 is what I need.

If I purchase a set of two to test, how easy will it be to move them from window to window to make sure I'm not wasting money by buying all 14 balances just to find out the windows aren't level?

Thank you,
Steven