If your windows just won’t stay up when you open them, you will have to repair or replace the mechanism that holds it up. In older windows there is a cast iron weight attached to a cord of rope or other material. In newer windows you will find that it has what is called a spiral balance. Most likely the spring inside the balance has worn out and you will need to think about Replacing Window Spiral Balances in each window that won’t stay open.
There are two types of windows, the tilt kind and the non-tilt kind, and although Replacing Window Spiral Balances in each kind is similar, there are differences in how you remove and replace the balances.
The first thing you must do is get the correct spiral balance for your window. You need to make sure that it has the rating to hold the weight of your window sash. The best way to ensure that you have the correct rated balances is to contact the manufacturer of your window to see if they carry replacement parts. If you can’t find the name of your window manufacturer then you will have to go to a window and door repair place and see if you can order the correct size and rated spiral balance for your windows.
Once you have the correct balance you can go to work on replacing the old one with the new one. For a non-tilt window you have to find the stop bead located on the left or right side and unscrew all three screws, starting at the top, then the middle and finally the bottom. You then remove the stop bead. If the window jam is painted you may have to pry the stop bead off with your putty knife or flat head screw driver.
You will need to get a grip on the left spring tape and pull some slack out with the tensioning tool or a pair of needle nose pliers. The tool is specially made for removing and winding the balance. Grab hold of the connecting hoop and disconnect it. Repeat the process for the right side balance tape.
With the balances disconnected just slide it out of the frame through the side with the stop head off.
You then remove the screws holding the old balance to the window jam. You will want to take care not to damage the holes because you will install the new spring balances in the same place.
Put the new spiral spring balance right where the old one was mounted and put the screws in on the top and bottom edges. You can use the same screws you took out of the old balance. Once you have all of the screws securely tightened you can repeat the process on the other side. The balances are able to fit either side so you don’t have to worry about which one goes on which side.
When the new spiral balances are installed all you have to do is replace the window the same way you removed it and your job is finished.