Why Won't My uPVC Window Stay Open?
For a side-hung or top-hung uPVC casement window that opens normally but slowly falls, swings shut or will not hold the position where it is left.
What this usually means
Most casement uPVC windows rely on friction stays to support the sash at different opening positions. Everest notes that a window that is too loose and will not stay open can need the friction on its stays adjusted, while worn or damaged hinges may need replacement. Check first that the hinge tracks are clean and visibly secure. Do not wedge a heavy sash open or lean outside to adjust upper-floor hinges. If the sash drops despite clean, intact hardware, a window repair specialist should adjust or replace the friction stays.
What may be causing this
The friction stays have lost adjustment or friction
Clues: The sash moves freely but gradually drops or swings shut.
What to do: Have the stays adjusted using the correct hardware procedure or replaced if worn.
The hinge tracks are dirty or contaminated
Clues: Movement is inconsistent and debris is visible in the track.
What to do: Clean accessible debris and use only lubricant approved for the hardware.
A friction stay or hinge is worn, bent or loose
Clues: The sash sits unevenly, rattles or one hinge arm moves differently from the other.
What to do: Arrange hinge replacement and sash realignment.
The sash is unusually heavy for the fitted hardware
Clues: The problem recurs after adjustment or replacement with underspecified stays.
What to do: Have the correct hinge size and weight rating confirmed.
How to check what is happening
The friction stays are not providing enough holding force.
The hardware needs cleaning, adjustment or replacement.
Alignment or hinge wear may be involved, not just friction adjustment.
Can you fix this yourself?
Cleaning visible hinge tracks is reasonable from a safe position. Adjustment or replacement is better left to a window repair specialist where the sash is heavy, high-level or misaligned.
- Soft brush
- Torch
- Window hardware information if available
What you can safely try
- 1
Keep control of the sash
Do not let a loose window slam while you inspect it.
- 2
Clean visible friction-stay tracks
Remove loose dirt without dismantling the hinge mechanism.
- 3
Look for hinge wear or sash drop
Uneven gaps or a bent stay point to repair rather than simple cleaning.
- 4
Arrange hinge adjustment or replacement
Correct friction stays should hold the sash securely without making operation excessively stiff.
Call a glazier if…
- The sash falls suddenly or feels unsafe to control.
- A hinge is bent, cracked, loose or pulling from the frame.
- The window is at height where hinge access is unsafe.
- The sash is also badly misaligned or cannot lock securely.
Get the right glazier.
We already know this problem maps primarily to a glazier. Choose the closest type of work, add your postcode and continue in the form.
Sources used for this guide
We prefer primary UK guidance, regulators and manufacturers for technical and safety-sensitive claims.
- How to Fix Stiff/Loose Window Hinges (uPVC)Everest
- When to repair or replace your windowsGlass and Glazing Federation
Last reviewed: 6 September 2026. Home Manual updates review dates only when the substance of a guide is checked or changed.