Window sash

Question

Hi. I have an older window sash, from a house built in 2005, that I need to replace. It's marked as 28F USB. It's a one-half inch channel with a length of 29 inches. The photos I uploaded show the broken sash next to a new one - one of your models, 2820. The new one is on top. Note that the spring in the one I'm trying to replace is longer than the one in the new sash by about two inches. The diameter of the broken spring also appears to be larger.

Bob · Accepted Answer

Thanks for posting. Just to clarify, these are called channel balances. The window sash is the moveable part of the frame with glass that these balances regulate the movement of. Don't worry too much about the inner configuration of the spring; in this particular case, that just comes down to different versions of this balance. In the past you have ordered the S380-29; assuming these are from the same house, then this is very likely what you need again. Just make sure the depth of the bottom nylon shoe, or the measurement from 'heel' to 'toe', is 1". Let me know if it differs at all. See the diagram below for reference. As far as the stamp option to select, 28F likely conforms to our stamp option of 2860, which means this balance can support a window sash in the weight range of 32 through 35 pounds. Let me know if you have any questions.

Comparison of the S378, S380 and S385 balance shoes.