Help me with part Identification?

Question

I am hoping for help in identifying the part pictured above. Its from a vinyl double Hung bottom sash. The metal channel is 26 inches long with the marking 25 3 Caldwell HM. The only other marking I could find was a C on a small aluminium hook at the end of the spring. Also if you have a link showing the installation of the part it would be helpful since when I was looking at the bad one the good one on the otherside fell out. I'm not really sure how to even remove this sash.

User submitted photos of a window balance.

Tom · Accepted Answer

With this combination of attachments, you could have either a Series 380 or Series 385 channel balance. You need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment. You'd have the S380-26 or S385-26, due to the 26" length of your balance:

Comparison of 15-004 and 15-005

The 25 3 and "C" markings are both equivalent to our SWISCO 2530. This just refers to a certain length and a certain spring strength, but it's an important indicator when you're choosing the proper balance. It's known as a weight "option." Sometimes people notice that "25" is close to the 26" length of their balance. There is a reason for this, but don't worry, the numbers are not supposed to be the same.

You'd weigh your window sash if you want to be sure that the 25 3 balance originally used on your windows was the right one. (After all, we can only match the identity of the balance the last installer/repairer used, which may or may not be the ideal balance.) Every option has a certain weight range that it holds securely, so you'd see if your window sash falls within that range. The 2530 holds 15 to 19 pounds.

As for the removal of the sash and the replacement of the balance, you can see our Youtube video on the topic: