Symptoms
- Sash slides down as soon as you let go
- Used to hold position, now drifts
- Only happens on one side
- Requires a stick or object to prop it
Likely causes
- CommonBroken or stretched sash cordOlder double-hung windows use ropes and counterweights that fray and snap over time.
- CommonWorn-out spring balanceVinyl and newer wood windows use spring or block-and-tackle balances that lose tension with age.
- PossibleBalance shoe disconnected from the trackThe plastic shoe that rides in the jamb channel can pop out or crack.
- Less commonWrong balance tension for sash weightA balance replaced with the wrong size won't hold the sash's weight.
What to do
- Open the window and look along both sides of the sash for the balance mechanism or cord.
- For spring balances, check whether the shoe (plastic clip) has popped out of the side track and snap it back in.
- For corded sash-and-weight windows, remove the interior stop molding on one side to access the sash and weight pocket.
- Inspect the cord for fraying; if broken, note the sash weight (often stamped or estimated by size) for a replacement.
- Replace the broken cord or the full spring balance cartridge, matching the size and tension rating to your window.
- Reinstall the sash, test it opens and holds at several heights, then replace the stop molding.
- If both sides are worn, replace both balances together so the sash sits level.
Tools and parts
- Screwdriver
- Pry bar
- Tape measure
Window sash balance kitSearch: “window sash balance replacement kit”
Sash cordSearch: “sash window cord rope”
When to call a pro
Call a window repair company if you can't identify the balance type, the weight pocket is hard to access, or you have multiple failing windows at once.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.