Plan with confidence
Why won’t my uPVC window close or lock?
Common things to note when a uPVC window sticks, will not meet the frame or no longer locks smoothly.
A stiff handle can be a sign of an alignment, hinge or locking problem. Avoid forcing it; note how the sash meets the frame and ask for an assessment if it remains difficult to operate.
Notice what happens as it closes
Check whether the sash appears to catch at one corner, whether the handle turns fully and whether the locking points line up. Do not lean or climb to inspect an upper-floor window.
A changed fit can have several causes. These observations are clues for the repair team, not a reliable diagnosis or a reason to adjust safety-critical hardware yourself.
Avoid forcing the handle
Forcing a stiff mechanism may cause additional damage or leave the window unsecured. If the window will not lock, consider appropriate temporary security steps for the property and contact a suitable repair provider.
Do not dismantle multi-point locks or alter hinges without knowing the mechanism. Keep children away from an opening that cannot be secured.
What the repair assessment checks
A repairer may inspect the hinges, locking points, handle and sash alignment, then explain which parts can be repaired. Frame condition and compatible replacement parts can affect the option.
Tell the team the frame material and any markings you can read safely, the number of affected windows and whether the problem changed suddenly.
Explore your next step
General planning information updated 29 September 2026. Product specifications and the work for your home are confirmed in your quotation.