Need help to identify window balance for GAPCO window

Question

Hi,
Please kindly help me to identify part number of my window balances for a GAPCO window. Attached are pictures showing the pair of balances (exhibit A) from one window, one of its channels with stamped serial number "2390 T B.S.1 27" (exhibit b) and the other of the the pair with imprinted serial number 2330.

Jasmine · Accepted Answer

Thanks for writing in! It looks like you have either the S380-24 with a 1" shoe or the S385-24 with a 1-3/32" shoe. The metal channel of these balances is 24".

To determine which series is needed for your window, look over the dimensions from the diagram below to confirm the depth of your bottom shoe. I would be sure to confirm this measurement from both of your balances. Let me know if it does not match either measurement.

Comparison of the S378, S380 and S385 balance shoes.

Since you have a two different stamps on your balances, it would be best to obtain the exact weight of the sash (window). The 2330 stamp indicates that these balance should support a sash of 15 to 18lbs. However, I am unable to cross-reference the 2390 stamp. So the best way to determine exactly what stamp you need is to get the weight.

Once you have the weight there is a chart below the product description of the balance you need. You'll be able to determine the stamp you need based on the weight ranges listed there.

Please let me know if you have any questions.