Window Balance 27 4 EX CMC

Quick Learner from Escondido, CA

Sep 6, 2016 6:09 pm

Need to replace window channel balance. It is 28 inches long (not including plastic ends). Has the following printed on it : 27 4 EX CMC

User submitted photos of a window balance.

6 Replies

Tom from SWISCO

Sep 9, 2016 11:09 am

Hello! Please see our S385-28 channel balance with a 2740 option. I think this may be a good match, but look over our information to confirm.

Quick Learner from Sacramento

Sep 19, 2025 10:08 pm

Hello, this is also my exact balance, identical marks and 1-3/32" bottom. I ordered your S385-28 channel balance with 2740 option. Good fit, but they seemed too strong and difficult to close, even bouncing back up from the closed position. I figured they would lose a little spring and break in, but now 5 years later they are still way too strong (easy to open, hard to close). I see in other discussions that you recommend going down to 2730 for windows under 19lbs. My panes are 22.5lbs, about 30"x32" double pane. What might be the issue here when my panes are well into the listed 2740 range?

Tom from SWISCO

Sep 25, 2025 1:16 pm

If your sash is precisely 22.5 pounds, then the 2740 stamp should have worked fine. This is calibrated to hold 19 through 26 pounds.

Can you verify that the old balance was identical to the replacement in every last respect? Even a small difference may be hugely impactful. Seeing the originals would allow us to give better analysis.

Otherwise, based on the data you've provided, there's no reason why the 2740 would be acting this way.

Quick Learner from Sacramento

Oct 2, 2025 11:28 pm

Sure. Here is my original next to the 2 Swisco stamped 2740, one Swisco had the cord fail. That's why I'm looking to get more, just better balanced. I weighed a few more sashes and they're all over 22lbs. I tried the 2740's on a few panes and eventually split them up so a couple sashes had a 2740 on one side only, which was closer but still too strong. Thanks for the reply, looking forward to figuring this out.

2 user uploaded images

Tom from SWISCO

Oct 7, 2025 9:44 am

Thank you for your patience in this matter. Looking at your photos, I see no reason why your balances have failed. For a 22.5 pound sash, our hardware should have functioned without issue.

Since the only issue seems to be that the balance is too strong, you could go with the weaker 2730 stamp and see if that works better. However this is only designed to hold 13 through 19 pounds. It's technically not supposed to work on your sash, since it's too weak, but I can think of no other possibility.