How to Fix a Window That Won't Stay Open

A window that slides shut on its own is annoying and potentially dangerous — a falling sash can injure fingers. The fix depends on the window type, but most solutions are quick and inexpensive.

Why Won't My Window Stay Open?

• Broken sash balance: The spring or cord counterweight that holds the sash up has failed (most common in double-hung windows)
• Worn or weak balance tension: The balance is still working but has lost tension over time
• Broken casement stay: The arm that holds a casement window open has failed
• Window is too heavy: The balance isn't rated for the window weight
• Channels are too slippery: Over-lubrication has made the sash slide too freely

Fix 1: Replace the Sash Balance (Double-Hung Windows)

The sash balance is the most common culprit. There are two types:

• Spiral/tube balance: A metal tube with a spring inside; visible at the sides of the sash
• Block and tackle balance: A cord and pulley system inside the frame

To replace: remove the sash, unscrew the old balance, and install a new one matched to the window weight and height. Replacement balances are available by window brand at hardware stores.

Fix 2: Adjust Balance Tension

For spiral balances, tension can be adjusted by rotating the tube. Insert a flathead screwdriver into the bottom of the tube and turn clockwise to increase tension. Test after each quarter turn.

Fix 3: Use a Window Support Stick

The classic temporary fix — a wooden dowel or stick cut to the right length to prop the window open. Not elegant, but effective while you source replacement parts.

Fix 4: Install a Window Sash Lock or Stopper

A sash stopper or window wedge can be installed in the channel to hold the sash at a specific height. These are inexpensive and available at hardware stores.

Fix 5: Fix a Casement Window Stay

For casement windows, the stay arm (the hinged bar that holds the window open) may be bent, broken, or have a worn friction joint. Tighten the pivot screw first. If the stay is broken, replace it with a matching unit.

Fix 6: Reduce Over-Lubrication

If you recently lubricated the channels and the window now slides too freely, wipe out excess lubricant with a dry cloth. A small amount of friction is needed to hold the sash in position.

Safety Note

Never leave a window propped open with an improvised stick as a permanent solution, especially in homes with children. A falling sash can cause serious injury. Fix the balance properly or install a window stopper.