Need new part - window will not stay open

Question

I need to replace two of these as my window will no longer stay open. The window is very heavy!

The width of these are 1/2 inch and they are 30' long.

User submitted photos of a window balance.

Tom · Accepted Answer

Hey, thanks for posting. I've narrowed this down to two possible channel balance Series: either our Series 380 or our Series 385 balances.

Now, as you can see, there is only one difference between these two Series, and that is their bottom shoe. The Series 380 uses the 15-005 while the Series 385 uses the 15-004. I can't quite tell what you have based on your pictures, though. Please carefully compare their dimensions to your own hardware and see which is a better match.

Comparison of 15-004 and 15-005

We also do not have an option that corresponds to your stamp of 29-9. I would like to know the exact weight of your window sash so that we can determine what would work best with this balance.