801020

I'm afraid I'm not familiar with that part number. I'm not sure what 801020 might be in our inventory. Would it be possible to see photos of the hardware in question? Since it sounds like it's a coil balance assembly, I'd specifically like to see the pivot shoe, cover, and springs. I'd also like you to tell me how thick the coils are.

Hey there! We were able to track this number down after all and I believe you're looking for our 15-150D. This is a cover used for the 1/2" wide Series 160 coil spring. 

Sorry for the confusion! Hopefully this helps clear things up. Now, I would still need to see the pivot shoe in order to identify a match, since the Series 160 is compatible with many different styles. However, if your original is in undamaged condition then you can easily reuse it. That's one of the benefits of coil balance assemblies.

Thanks for getting back to us! That shoe appears to be a match for our 15-199. This is very commonly used with the Series 160 spring, which in turn uses the 15-150D double support. You may just want to check to make sure that your spring is the same width at 1/2", but otherwise I feel confident that these are the parts you want.

Since your sash is 20 pounds, and since our Series 160 spring is weighted in .5 pound increments, I would recommend using a 4.5 and 5.5 spring on each side. That will give you 20 pounds of total support, which should be perfect.

When the springs are too strong for the weight of the sash, then you'll find that the window is much harder to close. It may even pull up on its own after you shut it in extreme cases.

The extra force needed to close a window in that state could cause additional strain on the coils, but I'm not sure it would be so much that it would cause them to break early. Figure that most balances have a life span of around 10 years, maybe a little more if they aren't used too frequently. 

I agree that your springs are weighted way too strong for a 20 pound sash. That weight may be something you want to triple check just to be 100% sure. What might have happened is that the original installers didn't have the right weights on hand when they installed the window and so just put in whatever they had available. That happens more often than you'd think, especially these days when houses are getting flipped on the cheap.

You're very welcome! Please let me know if you had any other questions. We're always happy to help.