No markings
Thanks for posting. I am sure we can help, but to be safe, can you remove the sash so we have a clearer view of the pivot shoe in the window? The identity of the shoe should narrow down the coil balances you need. Many thanks.
Thanks for getting back to me. I think this might be the 15-140 Pivot Shoe, though I'd remove it to compare to be safe. This shoe works with Series 150 Coil balance springs sold separately. if your old coil housing is undamaged you can reuse it; otherwise see the 15-143, 15-144 and 15-145 components that 'sandwich' around each coil. Let me know if you have further questions.
This coil balance system is modular, meaning all parts are sold separately. For the replacement coil springs, you have to choose a spring weight for each replacement coil. The spring weight denotes the weight each individual coil can support. Look for stamps on the old springs that denote what to pick. If there are no stamps or you are unsure, you can weigh the window sash to determine what to do. See the video below.
