Hurd Windows & Doors review: Double hung springs breaking loose

We have 28 DH Hurd windows in our house which we purchased in 1999. Each window panel of the DH window mounts onto a pair of plastic "shoes" which slide up and down along with the window panel. Attached to each shoe is a spring to support the weight of the panel so there are 2 shoes and 2 springs per panel. We have not had any problems with the upper panels but we've had lots of problems with the lower ones. Since the springs are under a good bit of tension, the plastic shoes tend to break over time and when they do the springs retract upward slamming into the top of the window frame with a loud bang. Of our 28 windows, 1 lower panel is still intact, 14 have had 1 shoe break, and 13 have had both shoes fail. To repair these windows, at a minimum the shoes have to be replaced and they are luckily not expensive. However, in most cases the spring has hit the top of the frame with such force that the spring is bent out of shape and might have to be replaced as well. Springs cost a bit more, are sized specific to the window so can a bit more complicated to order, and are only sold in pairs. Even worse, in some cases when the springs hit the tops of the window frames, they also crack or break away portions of the plastic side rails that the windows slide up and down on. If this has happened, it gets really pricey. The rails are sold as complete assemblies with rails, shoes, and springs all included, are once again sized specific to the window and only sold in pairs, running between $100-120/pair! These windows are cheaply made with a lot of plastic and they do not last. Be warned.