Double hung window channel balance

Handy Person from Hamilton, Ontario

Aug 20, 2026 7:52 pm

Hello,

I am trying to replace my double hung window channel balance's but I'm not sure exactly what series I need from your website. Unfortunately the current ones I have are broken so I'm finding it difficult to tell which one is right. The marking on the one I currently have says 18 9BSI TF. I've included a picture of this.

if it matters the channel on the window where they slide is smooth, no grooves or anything. I was looking at the 19" series 390 maybe? Is this correct? Thank you for your time and help!

4 user uploaded images

7 Replies

Bob from SWISCO

Aug 23, 2026 2:32 pm

Hey there. is there a version of this channel balance with the top attachment still intact, perhaps from the other balance in this window? If so, can you show us? I need to see both attachments to confidently identify this. Also, your balance's stamp option (which designates its strength) is from an outdated system. Please obtain the exact weight of the window sash the balances support. That'll narrow down the stamp option.

Handy Person from Hamilton, Ontario

Aug 27, 2026 5:30 pm

Hi Bob,
Thank you for your quick response. I weighed the window sash and it was 28.3lbs. I also took the other balance out that seems to be fully intact and have attached the photos

5 user uploaded images

Handy Person from Hamilton, Ontario

Aug 27, 2026 5:31 pm

Here is one more picture of the top attachment

1 user uploaded image

Bob from SWISCO

Aug 31, 2026 3:22 pm

Perfect, thanks! I think our Series 350 is the best pick here. This has a 19-002 top and 15-005 bottom fitting, so as long as those match then that's going to be our winner.

The more disqualifying detail here is the sash weight. Our S350-19 caps out at the 1850 stamp, which holds only 20 pounds at most. Please give us a little more time to look into the availability of a heavier spring and I'll get back to you ASAP. In the meantime, it would be a huge help if you could verify that the Series 350 is a match other than that detail.

Handy Person from Hamilton, Ontario

Aug 31, 2026 7:55 pm

Hi Bob,
I do think that the 350 is the correct one as well. I'll wait to hear back from you about the stronger spring before ordering.
Thank you!

Bob from SWISCO

Yesterday 12:23 pm

Okay, we're good to go on our end. It looks like the best stamp for your application would be the 1870, which we cannot provide as a stock option due to its extra heavy duty calibration (25 to 29 pounds). We can only supply this as a custom order.

I'll go ahead and email you a purchase link and price quote for 2 balances, which you can use to add them to your cart. Please let me know here if you wanted to make any changes to the quantity, or otherwise had follow up questions.

These need to be made from scratch, so expect a lead time of approximately 5-6 business weeks.