uPVC window maintenance: cleaning, seals and adjustment

uPVC and aluminium windows need very little maintenance. Clean the frames twice a year with mild soapy water, never with abrasive cleaners or solvents. Clear the drainage slots at the bottom of the frame, put a drop of oil on the moving hardware once a year and check the seals. That keeps the window airtight and easy to open.

By Marcio Barros · Updated 31 October 2026 · 4 min read

How to clean uPVC windows: twice a year

The glass: water and an ordinary glass cleaner, with a squeegee or a microfibre cloth.
The uPVC or aluminium frames: warm soapy water and a soft cloth. Rinse and dry.
The drainage slots and holes at the bottom of the frame: remove dust and leaves so rainwater can drain away freely.

What to avoid

Solvents (acetone, white spirit) and abrasive cleaners.
A pressure washer used up close, which can damage the seals.
Scouring pads on powder-coated or foiled surfaces (woodgrain finish).

Window seals

The seals keep the window airtight and watertight. Clean them with plain water and check that they stay supple. A cracked or flattened seal can be replaced without changing the window.

Hinges, locks and adjustment

Once a year, oil the moving parts (locking mechanism, keeps, hinges). If the window rubs or does not close properly, an adjustment is often all it needs. If the frame is warped, the glazing has misted up between the panes or the draughts will not go away, it is usually a sign that it is time to replace your windows.

Is aluminium maintenance any different?

It is almost the same. Powder-coated aluminium weathers well but does not like abrasive products. White uPVC is very easy to clean, while woodgrain finishes need a soft cloth. See our comparison of uPVC vs aluminium windows and our uPVC windows.

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FAQ

What is the best way to clean uPVC window frames?

Use warm water with a little mild soap or washing-up liquid and a soft cloth or non-scratch sponge. Avoid acetone, solvents, scouring powder and abrasive pads, which dull or scratch the frame.

Do uPVC windows need to be oiled?

Yes, once a year. Put a drop of resin-free oil or grease on the moving parts of the hardware, then open and close the window a few times to spread it.

How do I know if my window needs adjusting?

If it rubs, is hard to close or lets in a draught when shut, adjusting the hinges or keeps is often enough. With the right key it takes a few minutes.