Windows that don’t slide smoothly, don’t stay up when opened, or open at a crooked angle are a nuisance. Modern double-hung and single slider windows that open up and down have a balance system installed in the frame that guides the window and holds it in place. When a channel balance becomes disconnected or damaged it will prevent proper operation of the window. Most of the time this is a relatively easy fix that can be accomplished with a flat head screwdriver and a little patience.
The purpose of window balances is to hold the weight of the sash as the window is opened and closed. They guide the window and allow it to open evenly. Additionally, balances hold the top sash of a double-hung window closed when it is not being used.
There are several types of balance systems including spiral balances, constant force balances, cord and weight balances, and block and tackle balances. Block and tackle balances or “channel balances” are one of the most common balance systems for modern windows and we will focus on these balances in this article.
Block and tackle balances are made up of two or more pulleys, a spring, and a cord. The pulleys or “blocks” are grouped together and help to reduce the load of the sash. The cord or “tackle” is pulled when the window is opened or closed and extends or squeezes the springs based on the movement of the window.
Removing and replacing channel balances can be done by following these simple steps.
Begin with the window in the closed position. You will notice small clips on both sides of the window jamb. These clips are inserted into small holes in the jamb. Using a flathead screwdriver, you can pop the bottom portions of the clips out.
Sash stops may be installed in the top corners of the window. Sash stops are small plastic components that prevent a window from opening all the way to the top. The sash stops should pop out with little effort.
Pulling the sash upwards will cause the channel balances to catch on to the takeout clips that you previously popped out. You should be able to see the bottoms of the balances under the sash. This will confirm that you are past the engagement point. You can then push the sash to one side, pull it out, and remove it from the window frame.
The balances should now be visible inside the frame. Each balance can be easily removed by pushing it downward and then sliding it upwards. This will pop the connected clip out of its hole in the frame. The balance is spring loaded so use caution during removal. You can then examine the balance to determine if it is damaged or if the cause of the issue was that it had simply come loose.
Balances are sized according to the dimensions of the window. Therefore, you will need to ensure that replacement balances are the same size as the originals. When you are ready to install the new balances insert the clip attached to the bottom of the balance back into the hole in the frame and slide the top of the balance under the takeout clip. Next, reinsert the sash into the frame with the top of the sash above the top of the balances. Wiggle the sash slightly back and forth until you feel it catch on the balances. Finally, push the sash down, push the takeout clips back into place, and replace the sash stops if applicable.
As was stated earlier, there are many kinds of window balances and methods for removal and replacement vary based on their design. Many balances can be replaced or adjusted by a homeowner without special skills or equipment. However, some repairs may require help from a contractor.
Check out the following video highlighting removal and replacement of a block and tackle balance: