Window balance question- sash weight

Question

I have a 31.5lb window, well I really have 4, all needing new series 385 balances. The 2850 tops out at 32, so I would be maxing it out. I will go with the 2860 for its 32 to 35lb range. My question is will the window raise any easier with the few extra pounds of lift?

Also, just out of curiosity, the existing balances are marked 29 4 IR, by Caldwel. Are they under rated for the 31.5lb windows?

Dale

Tom · Accepted Answer

No, the window will not raise more easily with a stronger spring. In fact, it won't work properly at all. These are delicate systems, and it's important that you only get exactly what you need.

The question is: what do you need? I think you may be confused on a few points. Your original balances are stamped with 29 4, which means your balances should be 30" long, not 29" long. You may want to double check that.

Assuming you do have the S385-30, then our 2950 option would be the best choice. Your original stamp of 29 4 (which is our 2940) can only carry 23 through 28 pounds, while the 2950 option carries 28 through 32 pounds.