A broken spring on a sofa or chair is a very common problem. With no-sag (also called sinuous wire) springs, it is almost never the spring that is the issue, but the clip that holds the spring to the frame. Luckily, it’s an easy problem to fix…that is, if you already have your sofa apart for reupholstery! It’s certainly possible to fix this problem without having to take the whole sofa apart however.
First, I will show you how easy it is to fix when the frame is exposed.
If your sofa does not require reupholstery, and you just need to fix that spring, carefully take off the bottom liner, and nail the clip to the face of the frame like so: