A window that will not lock is one of the most common — and most urgent — faults we are called out to across Dorset. It is frustrating, it lets in draughts, and above all it leaves a weak point in your home’s security. The good news is that it is almost always a repair, not a reason to replace the window.

At ACP Windows Ltd we are a repair-first company. When a uPVC window will not lock, the frame and glass are usually perfectly sound — it is the hardware doing the locking that has worn or failed. This guide runs through the common causes and how we put them right, keeping your existing window in place.

Common reasons a uPVC window won’t lock

Most locking problems come down to one of a handful of faults. Knowing which one you are dealing with helps explain why a repair — not a replacement — is the right fix:

• The handle spins or feels loose. The spindle inside the handle, or the handle itself, has worn so it no longer engages the mechanism. A new handle usually solves it.
• The handle turns but nothing locks. The internal locking mechanism (the gearbox that drives the locking points along the frame) has failed. This is one of the most common faults, and fitting a new mechanism restores secure locking.
• The window has dropped out of alignment. Years of use can wear the hinges and let the sash drop, so the locking points no longer line up with the keeps in the frame. Adjusting or renewing the hinges brings it back into line.
• Stiff or seized locking points. The mushroom cams and rollers that grip the frame can stiffen or corrode. Servicing, adjusting or replacing them restores smooth operation.
• Worn keeps or misalignment. Sometimes the parts fixed to the frame have worn, so the locking points no longer catch properly.

Why it is worth fixing quickly

A window that will not lock is more than an annoyance. It is an obvious weak spot in your home’s security, and it often lets in draughts around the sash as well. Because the parts involved are used every day, a small fault tends to get worse over time — a slightly stiff lock becomes one that will not engage at all. Sorting it early keeps the repair simple and your home secure.

We carry the common handle styles, gearboxes and hinge types, which means many repairs are completed on the first visit, and non-standard parts are normally on next-day delivery.

A repair, not a replacement

It is worth saying clearly: a window that will not lock almost never needs replacing. If the frame and glass are sound, replacing the faulty handle, mechanism or hinges restores full, secure operation at a fraction of the cost and disruption of a new window. That is exactly the repair-first approach we take on every job — you can see the full detail on our window hinges, locks and handles service page.

We also carry out repairs to windows and doors damaged in a break-in, quickly restoring them to full working order by replacing any damaged hinges, locks or handles.

What affects the cost

The price of a lock or handle repair depends on:

• Which part has failed — a handle, a full locking mechanism or the hinges
• The style and brand of the existing hardware
• Whether the part is a common stock item or needs ordering in
• How many windows are affected

We always explain what has failed and agree a clear price with you before we begin.

Local window lock and handle repairs across Dorset

We repair window locks, handles and hinges throughout Dorset, including Bournemouth, Poole, Christchurch and the surrounding areas. In many cases there is no need for a visit just to get a quote — email us a photo of the handle or window with a short description of the problem and we will come back to you with guidance and pricing.

If security is a particular concern, you may also find our additional security service useful. And when you are ready to get a window that will not lock put right, get in touch via our Contact Us page and we will help you sort it quickly.