Channel balance needed

A home owner from Miami, FL says:
I have very old windows (probably almost 50 years old) and need channel balances for them. Attached are photos of the top, the bottom, the hook installed, the back, and the engraved number 2920 BSI FA. The length of the metal part is 30 in and the total length top to bottom is 31in. I need the whole balance with the plastic parts at the top and bottom. The windows weigh approximately 15 lbs. Can you tell me what model channel balance I need?

I also need the channel top part that screws onto the window, but will send that in a separate message.

Thumbnail of the uploaded file named 4E4F558B-124E-4FD8-BB3A-8C3A59F76C95.jpeg
Thumbnail of the uploaded file named A8B14FED-A98A-43F5-B5A7-D76EE894A21A.jpeg
Thumbnail of the uploaded file named 19B08F4C-6005-4F06-954E-B0657C2DB643.jpeg
Thumbnail of the uploaded file named 6C7A6D96-D3B6-4E68-B068-C0B5791CDB16.jpeg
Thumbnail of the uploaded file named 4F0E3A24-232C-4AB2-85E3-A3C9AF997D8F.jpeg
A home owner from Miami, FL says:

I sent you a message about the channel balances I am looking for, but also am looking for the plastic top that screws into the window. See attached photos. I hope you can help me with my window project.
Thumbnail of the uploaded file named B47B0BCA-1CF2-4178-9B72-8E4B0D117E94.jpeg
Profile picture of Casey
Casey from SWISCO responded:


It looks like you have either our S351-30, with a 15-002 bottom attachment, or S390-30, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. You'll also need a 2920 spring strength option for your replacement balances. 

I don't recognize your top sash guide but I know someone who might. I'll have them take a look and we'll let you know what we come up with. Thank you!

A home owner from Miami, FL says:
Thanks Casey,

I measured the bottom and it looks like I need the 1 1/8" bottom attachment, so I will order a set of S309-30 to try it out.

Let me know when you find out about the top sash guide.



A home owner from Miami, FL says:
Hi Casey,
I measured the top sash guide.

Top width 1"
Bottom with 5/8"
Center of hole from bottom of top 3/16"
Total height 7/8"
Top depth 9/16"
Bottom depth 5/16"

I hope this helps.

A home owner from Miami, FL says:
Found it ...

Can I mix these with the channel balance you listed (S390-30)? It sounds like they are for channel balance S377-30 by Pan Am. Should I get the Pan Am channel balance instead?

What do you recommend I do?

Thanks for your help!

Profile picture of Tom
Tom from SWISCO responded:

I agree that the 18-042 would be our best replacement option for your top sash guide. These guides can work with many different balances as long as the dimensions match up to your original guide. Thank you!

Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 4-7 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at 856-317-6263 or at