Short answer: A uPVC door that will not lock is usually one of four things — a dropped door, a worn gearbox, a failed cylinder, or misaligned keeps. Some are a quick adjustment; one means a new multipoint mechanism. Dee Valley repairs uPVC door and window locks from £120, quoted before any work starts.
Do not force it. Once a uPVC door has started to stick, do not keep lifting and heaving the handle. That can turn a straightforward repair into a full mechanism replacement.
First, work out which failure you have
The symptom tells you a lot, and it is worth knowing before you phone anyone.
The key is stiff, sticks, or will not turn at all — even with the door open.
Usually the cylinder — the barrel the key goes into. Cylinders wear, and replacing one is typically among the simpler jobs on a uPVC door. This is also your opportunity to upgrade to an anti-snap cylinder if you have not already.
The handle will not lift at all, or lifts with real force.
Usually alignment. uPVC doors drop over time as the hinges settle and the panel expands in heat, so the locking points stop meeting the keeps in the frame. Often an adjustment rather than a part.
The handle lifts, but the key will not turn to lock it — or it turns and nothing engages.
Usually the gearbox inside the multipoint mechanism — the part that drives the hooks and rollers. Gearboxes fail with age and with force. This is the repair people postpone and then regret.
It locks, but only if you lift the door by the handle first.
Alignment again, and further along. Still fixable, but it is telling you the mechanism is being stressed every single time.
Our uPVC door repair service covers the full range of multipoint, gearbox, cylinder and alignment work described above.
What it costs
Dee Valley’s starting price for uPVC door and window lock repairs is £120, including VAT, with the job quoted before work starts. A cylinder-only anti-snap upgrade is billed under Lock Changes & Installations (Anti-Snap), from £90. Every job is quoted before work starts, whichever line it falls under.
These are Dee Valley Locksmiths’ own starting prices, last checked 17 September 2026. The full list of twelve services is in How Much Do Locksmiths Charge? UK Locksmith Costs Explained.
Why “just keep lifting it” is the expensive option
A multipoint mechanism is a strip of hooks, rollers and a gearbox, all driven by one handle. When the door has dropped, those points no longer line up with the keeps — so every time you lift and shove, you are loading the gearbox against a fixed obstruction.
Gearboxes are cast. They do not bend, they break, and they usually break at the worst moment: last one out of the house, in a hurry, or last one home at night. At that point you are not paying for an adjustment, you are paying for the mechanism, the fitting, and quite possibly an emergency visit.
A door that has become stiff is a door telling you to get it looked at now, before the gearbox fails.
What you can check before calling
- Does it lock when the door is open? Lift the handle with the door swung open. If it locks smoothly in the air but not in the frame, that is alignment, not the mechanism.
- Has it got worse in warm weather? uPVC expands. Seasonal stiffness that is getting worse each year is a dropping door.
- Is the key stiff in every position, or only sometimes? Consistently stiff points at the cylinder; intermittent points at alignment.
- Is there a gap down one side of the door that was not there before? The door has dropped.
None of this is a repair, but it means you can describe the fault accurately — which means a more accurate price on the phone.
For other everyday faults, see our guide to common door lock problems.
Frequently asked questions
My door locks but the key snapped in it. Is that the same job?
No — that is a snapped key extraction, which starts at £60, and the cylinder may survive it.
What does an anti-snap cylinder upgrade cost?
A cylinder-only anti-snap upgrade is billed under Lock Changes & Installations (Anti-Snap), from £90, and the price is agreed before work starts.
uPVC door sticking, dropping, or not locking at all?
Call Dee Valley Locksmiths on 07777 472909 — priced before work starts, no call-out fee for work carried out, covering Wrexham, Chester, Oswestry and Shrewsbury.