Parts of a balance assembly

A new construction Balance assembly consists of coil springs, balance shoe, and balance cover. The springs are 1/2" wide for non-egress and 3/8" wide for egress.
Egress refers to a code rating in which 5.7 square feet of open area is achieved by raising the sash and not having to remove any part of the window. This is so you have room to get out in case of a fire. The size requirement is based on a firefighter in full gear.
The pivot bar is attached to the sash(the part of the window that moves up and down) and fits into the part of the balance shoe called the cam(the slotted metal piece).
The balance springs are rated to handle various weights of sash. There will be numbers stamped on the side of the spring indicating its pound rating, ie 3#,5#,6#. Replacement springs need to be the same size as the original. Too low on pound rating, the sash will slide down, too high on pound rating, the sash will raise on its own.
Springs are attached to one another through slots in the side of the springs.
The bottom spring is attached to the shoe through a slot in the shoe.
Depending on the age of your window the balance assembly you receive from the manufacturer as part of their parts only warranty may look different from what you currently have. This is OK the new styles will work. The main concern is the width of the springs. 1/2" springs can not be used to replace 3/8" egress springs.

video on replacing a coil spring balance

the camera was turned the wrong way!

tools needed for egress balance coil spring replacement:

1. flat head and phillips head screw driver
2. 1/2" chisel
3. side cutters
   

remove the old balance system.

• use the flat head screwdriver to turn the shoes cam and raise the shoe to the bottom of the springs
• remove the balance cover screw
• start from the top of the cover and work the old cover, springs and shoe out through the cutout on the mainframe.(it is OK to break the cover, you should have a replacement from the manufacturer)
• pre-assemble the balance assembly. there are 2 tabs on the top of the balance shoe that can be cut off with side cutters to allow more movement between the balance cover and the shoe
  
• begin inserting the new assembly from the top through the cutout.
• use the flat head screwdriver to pry cover and springs in slowly by angling the entire assembly in the balance track and then working them in through the cutout.
• use the chisel to remove vinyl residue left from the balance cover screw.
• place the balance assembly in the proper position.
  
• reinstall the balance cover screw. You can insert the screw just below the old hole to insure a tight hold into the vinyl
• use the flat head screw driver to lower the balance shoe into position for the sash to be re installed.