Channel balance needed

Question

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.

Casey · Accepted Answer

Hello,

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!

Comparison of the S351 and S390 balance shoes.