Window won't stay up

Hello, thank you for posting,

Please review the style and dimensions of the Series 140 coil balance that is 1-1/4" wide by 9/16" thick. Compare to your original to confirm a good fit! Your original metal coil should have a number stamp that indicates the weighed spring option needed.

If there are no markings, please provide the weight of the window sash to move forward. Thank you!