Which coil balance do I need?

Question

I believe I need an S180, but I'm not sure which lbs.

It's stamped with 7AE. Does that indicate I need 7 lbs?

The height of the window pane it supports is 21 3/4". The width is 28 1/2".

Thank you!

Tom · Accepted Answer

You may need 7 pound springs, but I'm not 100% sure. That "AE" marking isn't something I'm familiar with.

A good way to confirm is to simply weigh your sash on a scale, then divide that by how many springs support it. For example, if your sash weighs 14 pounds, and it's supported by two springs (one on each side), then 7 pounds would be correct.