Window Channel Balance ID and Replacement

Question

Hello,.one of the window channel balances failed, inquiring to ID the correct part and repalce both balances. Balances have been removed and need help selecting the correct replacement model that is available on your website. Marking on existing balance is: "20 4 KW CMC 11". Curent window is Double Hung, Non-tilt type, manufacturer might be Marvin, not sure though, been over 20 years since they were installed.

Bob · Accepted Answer

Thanks for posting. This looks like it might be either an S380-21 or S385-21 Channel Balance. The only difference between these two balances is the 'depth' of the bottom nylon shoe, as shown below. Measure your old balance's shoe to see what matches best. In either case, for a stamp option choose 2040.

Comparison of the S378, S380 and S385 balance shoes.