channel balance, springs are too strong

A home owner says:
Hi and thanks for your help.

I previously order part S380-27 (27" Series Channel Balance), option:2640, and it fits and works like a charm.

The problem I have is that the springs are too strong, making it hard to close the window. I'd like to re-order some different springs, but need to know what option would be best. I could weigh the window if that would help.

Thanks again.
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Tom from SWISCO responded:
Derek, unfortunately we cannot offer spring replacements for your channel balance. When a balance spring goes bad (or appears too strong) it is recommended you replace the entire balance unit.

What was the stamp on your original channel balances? If you are uncertain, please give us the weight of your window sash.
A quick learner says:
Sorry, I guess I wasn't clear -- I meant to say "I'd like to re-order some WITH different springs".

The originals were 2640s, the same as the replacement.

Sounds like I should weigh the window...
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Tom from SWISCO responded:
Yes, let's get the window sash weight before we consider any replacements.
A quick learner says:
The window sash weight is 15.4 pounds. What's next?

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Casey from SWISCO responded:
27" Series 380 with stamp option 2630 is recommended for window sashes that weight 13 through and including 19 pounds.

This 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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