SWISCO - The Replacement Hardware Authority

Window Balance

A home owner from Manahawkin, NJ says:
I am looking for replacement window balances. The balance closely resembles the S770-28 28" Series 770 balance, however I do not know what letter designation to add. On my balance I have BSI the numbers 2800 and the letters LE. The window panel it supports (2 requires) is 34" wide by 30" tall. Can you identify the replacement balance I should use? I would need to order 6 units, 2 for each of 3 windows.
User submitted photos of a window balance.
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Tom from SWISCO responded:
Thanks for posting! Before I can recommend an applicable replacement balance, I just need you to confirm the weight of your window sash so that I know we are choosing the correct stamp. You can do this by removing the sash from the window and placing it on a scale. Any common bathroom scale should do.
A home owner from Manahawkin, NJ says:
The sash weights 19.5 lbs.
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Tom from SWISCO responded:
Thank you! For the S770-28's option, I would select the 28C. This can support a window sash weight of 19 through 23 pounds. Let me know what you think!
A home owner from Manahawkin, NJ says:
Thanks Tom,
Just want to confirm. A pair of the 28C balances will support 19-23 pounds. Not just one alone. I need to put 2 in each window.

Wayne
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Tom from SWISCO responded:
That's correct. The weight range information is based on 2 balances per sash. Balances are designed assuming friction in the jamb weather-strip will carry a portion of the sash weight. Suggested sash weights are approximate.
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