Sash keeps closing....

Thanks for reaching out! I am confident that we can supply you with the replacements you need for your balance assembly however, before we move forward, I'll need to confirm one detail.

It appears you have (2) 10lb coils in the window which would indicated that the sash should weigh 20lbs however, you've also confirmed that the sash weighs 38lbs. Can you please confirm the exact sash weight?

Thanks for confirming. The difference in the amount of weight the coils can hold and the weight of the sash is likely why the sash keeps falling. The 20lb coils are not enough to support the entire weight of your window.

Detail of 15-252

Given the weight of your window, you'll need the 15-252 Inverted Universal Dual Support. These are compatible with the Series 160 coil balance spring. Since your sash weighs 28lbs I recommend (1) S160-6 and (1) S160-7 for both sides of the window.

The compatible mounting clip is part 16-032.

Dimensions for 16-032