Extended-Travel Channel Balance Quote

Thanks for reaching out to us. We can supply this balance, but it has to be a custom order due to its configuration.

Thankfully, your photos tell us everything we need to get started. Just note that our replacement balance will have wings on the bottom fitting, which yours currently lacks; there won't be any difference in terms of its operation, I just didn't want you to be surprised when you open the box.

What I'll do now is email you a purchase link and price quote that you can use to add 3 to your cart. If you're repairing two windows, you may want to consider bumping that quantity up to 4, though. You don't want to mix old and new balances or else the new balances are likely to wear out faster then they ought to. It's ultimately up to you, just let me know if you wanted to make any changes to count and I would be happy to.

Unfortunately, I don't believe those balances are going to work for you. There are a lot of differences beyond the shoe size and design, which is itself pretty significant. You're also dealing with a difference in metal channel length (28" compared to your 27-5/8") and the length of the cord. These are not small differences.

There is a good chance that the S390-28 will not install properly in your window. Even if you do get it in there, the window will not be able to close all the way like it should. In a worst case scenario you will rip the cord out of the pulley and irreparably damage the new balance. In a best case scenario, the same will happen but only after so many uses.

In all my years repairing windows, I have never heard of anyone who successfully got a standard balance like you bought to replace an extended-travel balance, though many have tried. In the most successful cases they only worked for a few months before breaking. Balances are very precise systems and you can't just put anything in there. 

It's not worth trying. You should return those balances for a refund when you get them and purchase the correct hardware.

You are correct: the Series 390 does not have a pulley wheel in the shoe itself, which is just one of numerous differences. Not to mention that the bottom fitting is an entirely different size and style. But those are just two differences among many.

The biggest issue you're going to run into is size. The balance you bought is too long at 28", whereas your original was only 27-5/8". What that means is that the Series 390 might stick out at the bottom of the sash. There is also the matter of cord length: these are called "extended-travel" balances because the cords are longer and allow for more travel. The Series 390 lacks this longer cord.

What you can expect during operation of the window is that the sash will not close all the way, either because the cord is not long enough or because the balance sticks out of the bottom. In your case, both issues are in play. Continued use of the Series 390 in your window will lead to the cord snapping (or breaking the pulley) and possible damage to the window frame itself.

Please understand that there isn't just one difference between the Series 390 and the extended-travel balance. There are many, many differences from how the spring is calibrated, to size, to extension limits, and a ton of other things. I know that they may look similar at first glance but they are totally different parts. 

To put it another way, using the Series 390 to replace your old balance is like trying to replace the tires on your car with those from a motorcycle. They're both round and they're both made of rubber, but it's just not going to work.

I have worked with your original balance many times and am very familiar with its operation and what can and cannot be used as a replacement. I am very confident that the Series 390 is not what you want. I know that having to order a custom balance is not ideal, but this is the hardware your window was made with and you really should stick with it. Like I said before, these are precise systems and you don't have a lot of wiggle room for alternative installations.