Broken channel balance

Thanks for posting. Good question. It sounds like to me one of your top sash guides broke. The top sash guides are nylon caps in the top corners of the window sash. Their purpose is to hold the channel balance in place during window operation. Over time, the top sash guides can break due to sun exposure and age. When this happens, the channel balance shoots past the sash and up the window track, exactly as you're describing.

We can help you replace the top sash guide. To get a hold of the runaway channel balance, you will need to manually press down on the top of the channel balance so it descends past the take-out clip, then use a flathead screwdriver to release the take-out clip. Then you must carefully raise the channel balance up to the take-out clip. Be careful indeed, as there will still be tension in the balance as you noticed. You will then be able to remove the window sash and take out the top sash guide. See the video below.

You can view our selection of replacement top sash guides here. If you need our help in identifying the right replacement, we will need to see an undamaged version removed from the window, with 'mugshot' pictures of the front and side.