Replacing several Caldwell window balances that have started failing.
25 4 BO Caldwell is the only information stamped on it.
the steel part of the balance measures 26inches. With the plastic top and bottom, it measures 27inches
Window ballance
Home Owner
Aug 29, 2026 6:01 pm
4 user uploaded images
4 Replies
Tom from SWISCO
Sep 3, 2026 9:17 am
Thanks for your photos. Based on what I see here, you have either our S380-26, S385-26, or S378-26 depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.
Comparison of the S378, S380 and S385 balance shoes.
Home Owner
Sep 4, 2026 8:15 pm
Thank you for your help! Any advice on spring strength? I don't have a matching stamp on the old balance. Should I take out and weight one of the sashes?
Tom from SWISCO
Sep 8, 2026 9:13 am
If your stamp is missing or too faded to read, then you will need to weigh your sash on a scale, yes. We have a weight chart on each balance's store page that tells you exactly how much weight each stamp supports.
One piece of advice: stronger isn't always better. You want the stamp to cover the weight of your sash; no more, no less.
