Do single hung windows use two tension coils?

Question

I am replaced the broken parts on a single hung window. I used parts I recently purchased that you suggested would work. My problem is when I open the window the sash clip drags on the coil guard and the clip either breaks or the plastic guard is chipped. What am i doing wrong? The window takes the 3/8 boot. It had two coils on each side. Help.

The window opens and closes with out damage but only when I use the sash clips to open the window and close the window when the clip is near the coil.

Tom · Accepted Answer

If I'm understanding your post right, it sounds like the tilt latch in your fourth picture is hitting the coil balance. This is an issue with some older windows; all modern coil balance manufacturers make coil balance systems assuming they'll be installed under the minimum threshold of the tilt latch. That way they don't pass over each other at all. If you mounted your coil spring under the lowest point of the tilt latch, would that fix the issue?