If your UPVC window handle is completely stuck and refuses to turn, you’re not alone. A locked UPVC window handle is a common issue in UK homes, and it’s usually caused by a small internal plastic tab or latch jamming inside the mechanism. In this step‑by‑step guide, you’ll learn how to open a UPVC window when the handle is locked in place, how to diagnose the problem, and what you can do to fix it safely and quickly.

Before attempting any repair, check that the window lock itself is fully unlocked and that the push‑button (if fitted) moves freely. If the handle still won’t rotate, the internal mechanism has likely failed, leaving the latch stuck and preventing the handle from turning. Fortunately, there’s a simple method to release it without damaging the frame.

Using a thin piece of flexible plastic—such as an old credit card or a strip cut from a plastic bottle—you can slide the plastic into the narrow gap between the handle and the window frame. This helps push the jammed plastic tab back into position, allowing the handle to turn and the window to open normally. It’s a quick, effective fix that works in most cases.

However, once a UPVC window handle mechanism has failed, it’s unlikely to be repairable because most handles are sealed units. Replacing the handle is usually the best long‑term solution. This is straightforward: simply remove the two screws holding the handle in place, lift it off, and fit a like‑for‑like replacement.

If you need a temporary fix, you can apply electrical tape to hold the latch in place while the window is open, giving you time to buy a new handle. This guide shows you exactly how to get your window open again with minimal fuss.