New channel balances needed for non-tilt windows

Question

First, greatly appreciate it if you can assist me with this effort and apologize for the length of this message but I figured more information was better than less.

I need to replace the channel sliders for a couple of my double hung windows (photos are attached), and since the windows are 15+ years old, I am going to replace all of them at the same time.

I need the channel balance along with the plastic parts (catches on the clip) at each end of the balance. All of the metal channels for all 5 windows are 29 inches long (this does not include the plastic parts at each end) and 1/2 inches wide.

Here are the specs I have:
Front window: Photo attached, stamp say 2830, and window weighs approx. 12.5lbs.

TV & 2nd Bedroom windows: Photo is attached, stamp says 28 4 11, and window weight is approx: 26 lbs.

Windows adjacent to Front Door & Back Door: No photo as I did not want to take apart the window. The stamp format (red in color) is the same as back Window photo but the stamp says: 28 6 10.

I do not know why the stamp numbers are different for the last 4 windows as each window (the pane that moves up/down) are the same dimensions (30 inches high and 46 inches wide, double paned), so I assume that I would need the same channel specs for the last 4 windows.

Based on my research of your website, I believe I need your 29" 380 channel balances for all 5 windows, the Front window would be 2820 and the other 4 larger windows would be 2840 but I defer to your expertise.

Thanks again in advance for all your assistance and I look forward to hearing from you, Bruce

Emily · Accepted Answer

Hi there, Bruce.

We appreciate you reaching out to us. I'm afraid I can't confirm what Series of balances you may have. I would need to see clear and unobscured photos of the top and bottom fittings.

If all of these windows are identical, they should have the same stamps. My recommendation would be to weigh each sash to confirm the proper spring strength option needed for the replacements. Or you could stick with the original stamps on these balances if the windows have been working this whole time without issue. The decision is ultimately up to you.