A window dropping shut usually means the sash balance is worn, mis-set, or disconnected and needs inspection or reset.
When a sash slides down the moment you raise it, the counterbalance isn’t doing its job. That system carries the sash weight so the glass stays where you place it. The good news: most fixes are simple once you know the window type and the parts inside the tracks. This guide shows clear checks, safe steps, and when to swap a part or call a pro.
Window Won’t Stay Open: Common Causes And Quick Checks
Start by identifying the operating style and the balance parts you have. Modern vinyl and aluminum models use spiral or constant-force springs. Older wood units may hide ropes and weights behind side pockets. Tilt-in double-hung models also rely on a small metal piece called a pivot bar that locks into a shoe inside each side track. For a quick primer, this overview of window balance basics covers common systems and how each one supports the sash.
| Window / Balance Type | Typical Symptom | First Fix To Try |
|---|---|---|
| Double-hung with spiral balance | Sash drops fast; one side tilts | Re-engage or tension the spiral; reset the shoe positions |
| Double-hung with constant-force coil (block-and-tackle) | Slow drift down; both sides even | Inspect coil stack; replace worn spring pack |
| Old wood with rope-and-weight | Dead fall; rattling inside jamb | Open side pocket; re-string broken sash cord |
| Tilt-in lower sash with pivot bar | One corner hangs; won’t latch | Seat pivot bar in the shoe; align shoes to same height |
| Casement or awning | Won’t hold position; sags | Adjust sash and operator; tighten friction hinge screws |
Safety Prep And Tools
Glass is heavy and edges can bite. Wear cut-resistant gloves and eye protection. Lay a towel on the sill to protect finishes. Keep pets and kids away. Have a helper if the sash is large.
Tools: Flathead screwdriver, Phillips screwdriver, needle-nose pliers, adjustable pliers, tape measure, silicone spray, painter’s tape, a spiral-balance tension tool or small hook for some brands, and a cordless driver for coil packs.
Fast Diagnoses You Can Do In Two Minutes
Check The Locks And Tilt Latches
Make sure the window is truly unlocked. On tilt-in models, slide the tilt latches inward and return them fully. A half-engaged latch keeps the shoe from grabbing the pivot bar.
Inspect The Balance Shoes
Look inside each side track for a U-shaped shoe. Shoes must sit at the same height on both sides. If one is low, the sash cocks and drops. Use a flathead to rotate the cam to the “open” position, slide both shoes to the same spot, then rotate back to “lock.”
Test Spring Tension
Lift the sash six inches and let go. If it sinks, your springs need tension or replacement. If it rises, tension is too high. Balanced tension lets the sash hold at several heights.
Step-By-Step: Fixing A Tilt-In Double-Hung
1) Remove The Lower Sash
Raise it a few inches, release both tilt latches, and tilt the panel toward you until the top clears the tracks. Lift one side to free the pivot bar from the shoe, then the other. Set the sash flat on a soft surface.
2) Reset Misplaced Shoes
With the sash out, you can see the shoes clearly. If a shoe slipped to the bottom, use a flathead to rotate its cam to the release orientation and slide it up to match the other side. Repeat on the opposite track so both shoes are level.
3) Re-Tension A Spiral Balance
Hook the spiral tip with the tension tool, pull down, add a quarter-turn at a time, and seat the tip on the shoe. Two to four turns is typical for a light sash; heavier glass may need more. Work both sides evenly so the panel sits level.
4) Reinstall And Test
Insert one pivot bar into a shoe, set the other, and rotate the sash upright. Snap the latches home, then raise to several heights. If it still drifts, add one more quarter-turn per side or move to spring pack replacement.
When You Have Constant-Force Coils
Coil balances use a flat spring pack that lives behind a small cover near the lower third of the track. Over time, coils lose snap or the pivot shoe cracks. If the sash drops evenly, both sides may be tired. Replace in pairs so the lift matches.
How To Swap A Coil Pack
Remove the sash, unscrew the cover plate, support the coil stack, and lift it out carefully. Compare the stamped weight rating to your sash weight. Install the same rating or the manufacturer’s recommended upgrade if the sash was always heavy. Lubricate the shoe pivot lightly and reassemble.
Older Wood Windows With Ropes And Weights
Classic units move on cords and pulleys that counterbalance lead or steel weights. A broken cord leaves the sash unsupported. Pry off the interior stop, lift the sash, and access the side pocket panel to reach the weight well. Thread new sash cord over the pulley, tie to the weight, and knot into the sash groove. Replace the pocket cover and stops, then test.
Alignment Problems That Mimic Balance Failure
If the frame is out of square, the sash binds and pops the pivot out of the shoe. Check reveals: the gap should be even on both sides. Shim loose jambs, tighten frame screws, and re-seat the pivot. On casements, adjust the sash to center the reveal and snug the friction screws so the vent holds its position without slamming.
Parts You Might Need And Typical Costs
Here are ballpark parts and time ranges. Prices vary by region and brand.
| Part / Task | DIY Cost (USD) | Typical Time |
|---|---|---|
| Spiral balance (pair) | $15–$40 | 30–45 minutes |
| Coil spring pack (pair) | $25–$60 | 45–60 minutes |
| Pivot bar (pair) | $6–$20 | 15–30 minutes |
| Balance shoe (pair) | $10–$30 | 30–45 minutes |
| Sash cord set | $8–$15 | 60–90 minutes |
| Pro labor (diagnose/adjust) | $75–$150 | 20–40 minutes |
Detailed Troubleshooting For Stubborn Cases
Top Sash Keeps Dropping
On many tilt models the upper panel has its own balances. Remove the lower panel, release the tilt latches on the top panel, and repeat the same shoe reset and balance steps. Make sure the meeting rail locks latch freely; a jammed lock masks a sagging upper panel.
Only One Corner Drops
That points to a pivot bar that missed the shoe. Check for a cracked shoe cam. Replace the shoe if the cam spins freely or the spring clip is broken. Verify both shoes sit at the same height before setting the sash.
Sash Pops Out When Tilted In
The shoes might be in the “open” position. Rotate each cam back to the load position before attempting to seat the pivot. Some brands need a special hook tool; a bent coat hanger can work in a pinch.
Casement Or Awning Won’t Hold
Hinges include a friction screw. Open the vent, support the sash, and snug the screw a quarter turn at a time on both hinges. If the operator arm is stripped, swap the handle and gear box as a unit.
Care That Extends Balance Life
- Keep tracks clean. Vacuum grit, then wipe with a dry cloth.
- Use a dry silicone spray on plastic tracks and shoes. Avoid heavy oils that collect dust.
- Don’t slam the sash. Sudden drops bend pivot bars and crack shoes.
- Open both sides evenly. Lifting from the center prevents twisting the panel.
- Once a year, test holding power at a few heights and add a quarter turn to spirals if you feel drift.
When To Replace Instead Of Repair
If you see rotten wood, fog between panes, warped frames, or repeated shoe failures, a new unit may save time and energy. Replacement also improves air sealing and comfort. If a unit is under warranty, ask the manufacturer for exact parts and procedures.
Brand Guides Worth Saving
Some manufacturers publish clear procedures for resetting shoes and balancers. See Andersen’s guidance on tilt-shoe adjustment and guidance specific to many double-hung lines from the same site. These walk through alignment, reset, and testing steps with clear diagrams so you can match your parts.
Quick Reference: Fix By Symptom
Use this cheat sheet when you’re next to the window.
Drifts Down Evenly
Both balances are tired. Replace or re-tension in pairs. Check coil ratings match sash weight.
One Side Drops First
Reset both shoes to equal height. Inspect the low-side shoe for cracks and the pivot bar for bends.
Won’t Stay Up After Cleaning
Cleaning can move a shoe. Re-seat the shoes, then test tension again.
Locks Don’t Line Up
Realign the frame reveal and square the sash. Shim loose jamb screws. Recheck hold at mid height.
What Pros Do Differently
Technicians measure sash width, height, and glass thickness, then select balances with the right tip color or stamp rating. They pre-load spirals on the bench, replace shoes, and adjust reveals so the panel seals without drag. A trained eye spots a split jamb liner or bruised track that keeps eating parts.
Final Checks Before You Close The Toolbox
- With the sash installed, test at 4–5 heights for steady hold.
- Verify both tilt latches snap fully and the meeting rail lock engages without force.
- Reinstall child-safety stops if you use them.
- Wipe tracks clean and label the balance type for next time.