Channel balance for Milgard single hung window

Thanks for posting. Yes, if the shoe depth is greater than 1", then this looks like an S385-27. Double-check the window weight. Your balance's stamp of 26-5 correlates with our stamp rating of 2650, which denotes a balance meant to support a window sash in the weight range of 26 through 30 pounds. If your sash indeed weighs 25 pounds, then the balances you have should have been a bit too strong for the window. Have you ever had trouble closing this window, or keeping it closed, prior to the balances failing? If so that would confirm my hypothesis, and you'd want the stamp option of 2640 instead, which denotes a balance that can support a sash in the weight range of 19 through 26 pounds. That said, we always advise sticking with the original stamp option unless you clearly had the wrong one to begin with, so that's why I suggest checking the sash weight again to be safe. Let us know if you have further questions.