Coil Balance System Replacement

A home owner from Manchester, CT says:

Measurements for the piece are:

1 1/4 inch across the top

4 1/8 inch in height

7/8 inch thickness

I need to order two (2) of these for 2 windows.

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Bob from SWISCO responded:

Thanks for writing in. This is a Coil Balance system. Because of the modular nature of coil balances, each part is sold separately. The pivot shoe looks like our 15-192. This shoe is compatible with our Series 170 and Series 171 Coil Springs. The Series 171 is the second coil spring; it stacks on top of the Series 170. See the video below for details. You will need to look for stamp codes on the spring tape to know what spring weights to select. If there are none, or you are uncertain, weigh your window sash. Give us that exact weight, and we'll work out what you need. 

If your balance spring's old housing is undamaged, you needn't replace it. But if you want to, we sell individual housing components for each coil spring. See our 15-185 Spring Cover and 15-157 Balance Drum.

A home owner from Manchester, CT says:
Thank you for the information, sorry for the late response, there is a sticker on the side of the window, I'm not sure if that give the information for what spring weights to get, I will upload a photo of it. If not I can weight the sash. Thanks again.
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Bob from SWISCO responded:

No, I am afraid it won't. The only thing that will tell you the strength of each spring is the number printed on the springs themselves. If those numbers aren't there, or if they've worn off, then you will have to physically weigh the sash to get the exact weight for us. 

A home owner from Manchester, CT says:
Ok the weight of the window sash is 18.2 lbs.
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Bob from SWISCO responded:

Great. If the exact weight of the window sash is 18.2 lbs, then you could get away with using just our S170-409 on both sides of the window sash, so that you'd have just one coil spring on each side of the window, rather than two. This coil spring supports 9 lbs of weight individually. This would total 18 lbs of support, which would work for the exact weight you measured. Let me know if you need anything else.

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