Looking for help in identifying parts to replace balance

Question

Hello-!

I have a double hung window with one of the windows lost its constant force balancing, where it will just fall straight down.

So I've took apart one of the functioning unit and took measurements & pictures.

The failed unit have coils from the upper, smaller unit unwound partially and it is missing the anchoring point; where the spring would be mounted onto the window rail itself.

Anyhow, if I could get all the parts in relation to replacing the unit above as a whole, that would be much appreciated!

Bob · Accepted Answer

The bottom coil shoe looks like the S161-08; just make sure the width and thickness match what's listed on the product page. The top section is the 15-086 Tandem Housing, along with either an S180-6 6 lb spring, or S180-9 9 lb spring. Unfortunately, and frustratingly, there's no reliable way to say which is the right way to read that number printed on the housing! To know for sure, I recommend you obtain the exact weight of the window sash. Give us that exact weight and we'll work it out for you.