Why Your Window Won't Stay Open: A Spring Repair Guide
If a double-hung or single-hung window slides up fine but won't hold position — sliding back down on its own, sometimes slamming — the issue is almost always the balance spring system, not the glass or frame. It's one of the most common service calls we get, and one of the more misunderstood.
What a balance spring actually does
Older and many modern sash windows use a spring-loaded balance mechanism mounted in the frame channel on either side of the sash. The spring counteracts the weight of the glass, so the window stays wherever you leave it instead of needing to be propped or wedged. When that spring loses tension, breaks, or the mechanism wears out, the sash loses its counterweight and gravity wins.
How to tell it's the spring and not something else
- Spring issue: the window slides smoothly but drifts down or won't stay raised at all. No grinding, no binding.
- Frame issue, not spring: the window feels stuck, scrapes against the track, or has to be forced — that's usually a swollen, warped, or misaligned frame, not the balance system.
- Both: common in older installations where humidity has affected the frame and the spring has also simply aged out. Worth a real inspection rather than guessing.
Is it repairable, or does the whole window need replacing?
In most cases, balance springs are a contained, replaceable part — this is a repair, not a replacement situation, and one of the more affordable calls we make. The exceptions: if the frame channel itself is damaged or warped enough that a new spring won't seat properly, or if the window is old enough that matching replacement parts is impractical, replacement becomes the more sensible option.
What happens during a spring repair visit
Diagnose
We test the sash movement to confirm it's a balance issue rather than a frame or track problem.
Remove the sash
The window panel is carefully lifted out of the frame channel to access the balance mechanism.
Replace the spring or balance unit
Matched to the window's weight and channel size — this is not universal across window brands or ages.
Reseat and test
The sash goes back in and we test it through a full range of motion before calling the job done.
A word of caution on DIY spring kits
Generic balance spring kits exist, but window channels vary enough between manufacturers and window ages that a mismatched spring tension can do more harm than good — over-tensioned springs can crack a sash on release. If you're handy and want to try it yourself, at minimum confirm the spring tension rating against your specific window's weight before ordering parts.