Channel balance replacement - Peachtree

Question

I am changing the channel balances of the lower sash in a Peachtree double hung non-tilt cottage style window. Markings indicate 3672 1G, no stamp. I weighted the bottom sash at 24lbs. Old channel balance is 32.25 length, width 1/2in. I bought a new channel balance to fit D3672 window size, weight capacity 24-28lbs with 31.25-4 stamp. Once replaced, the window will not stay up, it falls. The weight of the window isn't being held up but for maybe 1/4in. from the bottom and I have to push down to close.
I replaced channel balances in a different size window that was not cottage style. Everything works fine in that replacement. Is it possible I need to go up in weight capacity for the cottage style window?
Thank you.

Bob · Accepted Answer

This indeed looks like our S745-32 to me. It certainly sounds like the balances for this specific window are too weakly calibrated. The best thing to do is to obtain the exact weight of the window sash. You can then match that exact weight with one of the weight ranges listed alongside each stamp option on the balance product page.