Thank you for reaching out to us. We believe you need the S600-27 spiral balance with a blue tip. A pair of balances with this tip color will support a sash weighing 12 to 31 pounds. Look this part over and let us know if you have any questions.
I installed these balances in four of my windows and unfortunately they do not move freely and are a little difficult to close. Opening is a bit easier but not optimal. When installing these balances I rotated the spirals about 4-5 times. Should I reset them turning less times? Thank you for your help. Doug
Yes, I believe you are charging the balances too tightly. First, tilt in the sash and remove it. With the 75-006 tool, unhook the spiral from the pivot shoe. Using a flat-tip screwdriver, place it in the center cam of the pivot shoe and turn it away from you to release the brake. With your hand, try sliding the pivot cam up and down the track. If it slides smoothly, the pivot shoe is fine, and reset it to the previous position on the track. Now with the balance, again install it to the top of the track, bring the spiral up to the blue nylon bushing, hook the 75-006 tool to the bottom pin, turn the spiral clockwise about three turns then hook it to the pivot shoe. Do the same on the other side and try the sash.
