Prism Window Won't Stay Up - Balance and Pivot Shoe Issue?

Thanks for posting. You certainly need a new pivot shoe since the old one is broken. Now, I'm afraid this exact pivot shoe and coil balance system are no longer made. Fortunately we have devised a replacement. Our 15-259 shoe should fit your window. However, to get it to work you'll also have to replace the old coil balance system with the Series 159 springs. We have a video that details this process. Take a look and let me know if you have any questions.

Hello again! If you haven't already, I highly recommend watching the video I shared above. This gives you a full list of all products necessary for this project (including the 15-255 support and 26-083 pivot bar).

As for coil strength, the only way you can learn that is by weighing your sash. That will require taking it out of the window and putting it on a scale. The rule of thumb is to divide the sash weight by how many springs support it. It doesn't matter if you have one spring per side, two springs per side, or three; as long as they add up to equal the sash weight, they'll work. But you have to weigh the sash on a scale. There's no way around that, unfortunately. It should be your very next step on this project.