Replace Window Balance

Question

Replacing window balance for 6 windows.  Window pane size for 3 windows are 30"&times;28.75".  Existing balancer have a stamp of 2940 but considering to switch to 2950 since these have already been replaced twice.  Please help confirm the correct replacement part.

Tom · Accepted Answer

Thanks for your photos. Based on what I see here, you have either our S351-30 or S390-30 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.

Regarding stamp option, if you have any doubts that the original stamp may be incorrect then your next step should be to weigh the sash on a scale. We have a weight chart for each channel balance in our inventory that tells you precisely how much weight each stamp supports. It's best not to guess.

Comparison of the S351 and S390 balance shoes.