Window Sash Spring Balancer - CertainTeed Double Hung Window

Hello! The shoe looks like our Certainteed brand 15-192, which means the spring is our Series 170. Unfortunately, without a stamp, I can't be sure what option you need. Can you tell me the exact weight of the sash? Please be as precise as possible, down to the ounce. Can you also confirm that your window only has one coil spring on each side?

Great! That makes things a lot easier. Typically, what we do is get the sash weight and then divide it by how many springs are on each side of the sash. In your case, 2. So for example, if your sash weighs 12 pounds, then you'd want an S170-406 on each side of the window. These carry 6 pounds each. 

The first two digits of the "406" portion of that product code represent how many inches of travel the spring has: 40". You'll note that the Series 170 has several springs that have the same weight capacity but different travel lengths, like 33" or 40". To clear that up now, 40" is standard in the industry these days. We opt to go for that in each instance.

If your sash is 16.3 pounds, then you can go with one S170-408 spring on each side. These carry 8 pounds each, which should be perfect.

The photos you're showing here look identical to the other balance system, so you would just go over everything we've talked about already to determine the best replacement.

Yes! That makes perfect sense. That's pretty much all there is to it, though I'm happy to answer any questions you may have about that process.