Why Does My uPVC Window Whistle When It's Windy?
For a closed uPVC window that makes a high-pitched whistle or hiss during windy weather, especially from one edge of the opening sash.
What this usually means
A uPVC window that whistles in the wind normally has a small air path through or around the window. Common causes include compressed or damaged gaskets, a sash that is not pulling evenly onto the seal, loose adjustment at the locking points, gaps around the frame installation, or intentional trickle vents creating airflow. Strong wind increases pressure across the window, so a tiny gap that is silent on calm days can become a loud whistle.
What may be causing this
The opening-sash gasket is worn, flattened or damaged
Clues: The whistle comes from one edge, there is a noticeable draught, or the rubber seal looks split, shrunken or permanently compressed.
What to do: The gasket may need cleaning, refitting or replacement with a compatible profile.
The sash is not compressing evenly onto the seal
Clues: Pressing gently on the closed sash changes or stops the whistle, or the window also feels slightly loose when locked.
What to do: The hinges, keeps or locking compression may need adjustment so the sash meets the gasket evenly.
A trickle vent is creating the noise
Clues: The whistle is clearly at the vent and changes when the vent is opened or closed.
What to do: Check that the vent is intact and fitted correctly. Do not seal it permanently if it is part of the home's required ventilation.
There is a gap between the window frame and the wall
Clues: The noise seems to come from the perimeter trim or reveal rather than the opening sash.
What to do: The frame-to-wall seal or installation gap may need inspection and resealing by a window fitter.
How to check what is happening
A local seal or sash-compression problem is likely.
The sash is probably not compressing the gasket firmly enough at that point.
The vent itself is the airflow path.
The gasket is no longer making a consistent air seal.
Can you fix this yourself?
Cleaning and inspecting accessible seals and checking the trickle vent are easy homeowner steps. Replacing a clearly removable gasket can also be DIY if the exact profile is matched. Hinge, locking-compression or frame-installation adjustments are better left to a window fitter if you are not familiar with uPVC hardware.
- Torch
- Clean cloth
- Mild soapy water for cleaning seals
- Phone camera for recording the leak location
What you can safely try
- 1
Locate the exact edge or vent producing the whistle
Wait for windy conditions and move around the window slowly. Note whether the sound is from the opening sash, trickle vent or outer frame perimeter.
- 2
Inspect and clean the gasket
Open the window and look for damaged, folded or dirty seals. Clean them gently and make sure they sit correctly in their groove.
- 3
Check whether sash pressure changes the noise
With the window closed and locked, press gently at the noisy edge. If the whistle changes, the sash alignment or compression needs attention.
- 4
Check the trickle vent without blocking it
Make sure the vent cover is secure and undamaged. Use its normal open/close control only; do not tape over a ventilation opening.
- 5
Repair the actual air path
Replace damaged seals or have the sash/frame adjusted so the window closes evenly. If air enters around the fixed frame, the perimeter installation seal should be inspected.
Call a window fitter if…
- The handle or locking mechanism is difficult to operate.
- The sash has visibly dropped or does not close squarely.
- The frame is loose from the wall.
- The only proposed fix is permanently sealing a required trickle vent.
- The window is at height and repair would require unsafe external access.
Get the right window fitter.
We already know this problem maps primarily to a window fitter. 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.
- Innovation by design – uPVC window gaskets and air leakageLiniar
- How Liniar Leads the Way in InnovationLiniar
- Whistling uPVC Windows: Why They Whistle in the WindGlass Tec Windows
Last reviewed: 31 August 2026. Home Manual updates review dates only when the substance of a guide is checked or changed.