Hello,
I am trying to DIY. Please see attached photos for the coil balance parts that I removed from bottom sash of my double hung window left side. What parts should I order? I see numbers 4 and 5 on the coils. The sash weighs 13 lbs. thank you so much. Should I replace both sides? Right side seems to be working ok.
Jody
Hey Jody. Thanks for all the thorough information! This is a 15-180 Pivot Shoe, which uses Series 190 Coil Balances. Stamps of 4 and 5 would indicate you need the S190-440 4 pound spring and S190-540 5 pound spring, respectively. However, that would equal 9 pounds of support on one side of the sash. Since the coil springs on both sides of the sash should be identical, that would mean you'd have 18 pounds of support total. You cite the sash weight at 13 pounds. Please double-check this if you haven't, since 18 pounds of support would be much too strong for that sash weight--you'd basically have trouble keeping the window closed!
Did you ever have that issue, before the coils broke? If so, it's possible you had too much support to begin with. Otherwise, please double-check if the weight is in fact 13 pounds. Let us know if it is, and we'll tell you what coils to order instead.
As to your other question, it is probably best to replace the coils on both sides at the same time. Coil balance systems technically are modular, meaning you only have to replace what is broken. So for instance, if your old housing is OK, you don't need a new support clip (15-181) or bushings (15-182). But balance springs tend to wear out faster when paired with older ones, so with the springs themselves, it's best to replace everything at once.
Let me know if that all makes sense, or if you have any other questions.
Thanks for verifying. In that case, you have a choice ahead of you: you can either stick with the same weight springs as you have now, which are too strong for the sash but still work anyway, or you can go with springs that are more closely calibrated for 13 pounds.
If you want to stick with the springs you have now, that would be the S190-440 (4 pounds) and S190-540 (5 pounds), for the springs marked 4 and 5, respectively.
If you wanted an assembly closer to 13 pounds, then I'd suggest using just one on each side: our S190-640 (6 pounds). Having one on each side will give you 12 pounds of support, which is one pound off, but that shouldn't be a big deal.
Since you'd only be using one spring per side, then you'd need to use a carrier that is designed to only hold that quantity. The 15-181 that I mentioned is no good, so see our 15-186 instead.
The ultimate decision will have to be yours. Please feel free to reach out if you had any questions.
