channel balance 30" 380 version

Question

I had ordered the 2950 version and used them on wider/heavier windows. Attempted to use these on 25 lbs windows and they keep moving past the window back to the stop clip. I am assuming the spring is just too strong for the lighter windows. However there is a slight groove in the frame that one side of the shoe travels in that is deeper than the other by about 1/8 of an inch. The shoes of the ones I'm taking out are wore down to 7/8 in an inch vs the new ones at 1 inch and there are 2 different numbers on the channels, both channel pictures are attached, along with the side of the frame, the top guide and bottom shoe.

Bob · Accepted Answer

Firstly, if the window weighs 25 lbs, a stamp option of 2940 would be the proper stamp option, as that option covers a sash in the weight range of 23 through 28 lbs. It appears someone replaced just one of the balances in your window when it broke. The other, stamped 29-9, is from an older rating system we no longer use; but the 2940 option would work for it all the same.

Can you double-check the shoe size? If it's just normally 1", then the S380-30 would be what you need. If it's in fact originally 7/8", we'd need to custom make balances for you with the 15-029 shoe attached.