Balance spring replacement

Question

I have a couple windows that need spring balances replaced. They are double hung and both tilt. The inside spring is 33" from top of screw hole to blue tip and the outside is 31" hole to blue tip.  I don't see a blue option for the 33". Should I get a longer or shorter size or a different color? Also the existing springs had plastic covers that disintegrated. The pictures are from the removed spring window. I measured the other window with springs attached and they are the same lengths.

Bob · Accepted Answer

What is the length of the outer tube up to and not including that blue tip? That's what determines the spiral balance length, not the inner spiral rod. If it's 31" long, then you need either the S600-31 or S900-31, depending on the outer tube diameter. We generally only see Blue Tips with the Series 600 though, so if you have the S600-31, then there is indeed a Blue Tip option.

If you have the S600-33, obtain the exact weight of the window sash. Then look at the weight ranges listed alongside each Color Tip option on the shop page to determine the Color Tip option you need.