Replacing Caldwell Channel Balances for my Window

Hello there. I'm confident we can help, but to clarify, the stamped codes actually do not designate the identity of the balances you need. Instead they merely tell us the strength or calibration of the balance in question. The actual identity of the balance, or what we call the Series, is determined by the nylon fittings attached at either end of the metal channel. Based on your photos you appear to have either our Series 380 or Series 385 Channel Balance. Both of these balances feature the 19-005 Top Winged Fitting, but use slightly different winged bottom fittings, or shoes. The Series 380 uses our 15-005, which has a depth, or 'heel-to-toe' measurement, of 1". The Series 385 uses the 15-004, which has a depth of 1-3/32". The picture below illustrates the difference. Since you clearly have a winged shoe, compare to the options depicted on the left. Let me know if your balances' shoes by some chance have a depth that does not match either option. 

Diagram on how to choose between the 15-001, 15-002, 15-004, 15-005, and 15-029 channel balance shoes.

Assuming you have either the Series 380 or Series 385, you'll then need to settle on the right length. This is determined by the length of the metal channel, not including the fittings at either end. Finally, you'll also need to select the right stamp options for the replacements. With all this information in mind, and going off your photos, I believe you need either the S380-18 or S385-18, with a stamp option of 1740, as well as either the S380-33 or S385-33, with a stamp option of 3240. Let me know if you have any further questions about any of this! 

Hey, Roger. I'm not sure why your window has two different sized springs, actually. If they look just like the balances the original poster photographed, then they absolutely should be identical. Have these windows functioned smoothly prior to the current balances failing? 

If you can confirm that you have either the Series 380 or Series 385, then check out either the S380-21 or S385-21. To know which of these two balances might work for you, you'll need to measure the shoe depth, or the 'heel-to-toe' measurement. If it's 1", use the S380-21. If it is 1-3/32", you'll need the S385-21. 

Once you determine the right balance, you'll need to choose a stamp option. While your old balance was stamped 20-2, the fact they are not identical on both sides of the sash makes me think we should be extra thorough on this step. I advise that you obtain the exact weight of the window sash. You'll note on the balance shop page there is  a list of all the stamp options options and how much weight each option can support. I recommend that you get that exact weight of your window sash, then match that weight to the weight range it falls under. Assuming the sash weight falls within our listed ranges, use replacement balances on both sides of the sash with the exact same length and stamp option. If your weight is different from anything we have listed, let me know and we can try to work it out for you.

I advise you go with the 2040. In this instance I think the 2050 may prove too strong for your window sashes. Let us know if you have further questions. 

Thanks for reaching out to us. Based on these photos, and knowing that you have the 15-004 bottom fitting, then my recommendation would be the S385-30. If you haven't already, you should look this balance over and see what you think.

Thanks for your photos. Based on what I see here, you have either our S380-20 or S385-20, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.

Comparison of the S378, S380 and S385 balance shoes.