Locksmith Guide
uPVC Door Won't Lock or Handle Won't Lift? Causes and Fixes
By Kenny, owner and locksmith at Open-in Security Services, Ickenham, working the same West London patch since 2006.
Published
The Short Answer
A uPVC door that will not lock, or whose handle will not lift, almost always has a fault in the multipoint mechanism or the door's alignment rather than the door itself. Common causes are a dropped door catching the keeps, a worn spring cassette, or a failed central gearbox. A locksmith can open the door without damage, replace only the gearbox from £85, or realign the door from £65, so a new door is rarely needed.
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Call 07904 594452 WhatsApp insteadIf your uPVC door will not lock, or the handle will not lift, the problem is almost always in the multipoint mechanism or the way the door hangs in its frame, and very rarely in the door itself. Realigning a dropped door starts at £65 and replacing a worn gearbox starts at £85, a small fraction of what a replacement door would cost. The checks below help you work out which fault you have, and when to stop and pick up the phone.
How a multipoint lock works
Run your hand down the edge of a uPVC or composite door and you will feel a long metal strip with several moving parts set into it. That strip is the multipoint lock. Lifting the handle drives hooks, rollers or mushroom-shaped cams out of the strip and into steel keeps screwed to the frame, and on most doors a deadbolt comes out at the same time. Turning the key then deadlocks everything so the handle cannot be pushed down from outside.
The component doing all the work is the gearbox, a compact cast housing sitting in the middle of the strip directly behind the handle. It turns the lifting motion of the handle into the sliding motion of the rods that run up and down the door. The euro cylinder, the part your key goes into, only throws the central deadbolt and locks the gearbox in place. It does not move the hooks, which is why a key can turn cleanly while the door still refuses to open.
Symptom to cause: what the door is telling you
Most multipoint faults announce themselves in a recognisable way. Match what your door is doing against the table below before you touch anything.
| What the door does | Most likely cause | Usual repair |
|---|---|---|
| Handle feels floppy, no spring in it | Broken spring cassette in the handle, or a tired gearbox spring | New handle, or a gearbox if the hooks no longer move |
| Handle must be lifted hard, or the door shoved, to lock | Door has dropped, or the keeps have shifted | Realign the door and adjust the keeps |
| Locks fine when open, will not lock when shut | Hooks are missing the keeps: alignment, not the mechanism | Hinge and keep adjustment |
| Key spins freely and nothing happens | Broken cylinder cam, or a failed gearbox | Replace the cylinder or the gearbox |
| Handle stuck in the up position | Gearbox jammed part-way through its throw | Non-destructive opening, then a new gearbox |
| Handle stuck down and will not lift | Gearbox has stripped, or the rods have jammed | New gearbox |
| Only misbehaves on hot days | Door expanding and binding on the frame | Alignment, sometimes hinge replacement |
Safe checks you can do yourself
None of these need tools beyond a screwdriver, and none will make the fault worse. If any step feels like it needs force, stop there.
- Open the door and operate the lock with it open. Lift the handle, watch the hooks come out, and turn the key. If everything moves freely with the door open, the mechanism is healthy and your problem is alignment.
- Close the door slowly and watch where it touches. Rubbing at the top corner on the lock side means the door has dropped; rubbing along the bottom edge usually points to worn hinges.
- Check every hinge screw is tight. Loose fixings on the frame side let the door sag a little more each month.
- Lubricate the strip, hooks and keeps with a dry PTFE or silicone spray. Do not use penetrating oil or household oil: it collects grit and gums up the gearbox.
- With the door shut, take the weight of the door on the handle as you lift to lock. If it locks that way but not otherwise, the door has dropped and needs realigning rather than a new mechanism.
- Do not force the handle. A stiff handle lifted hard is how a worn gearbox becomes a broken one, and a broken gearbox can leave the door locked with you on the wrong side of it.
Why heat and cold change how the door locks
uPVC expands in warm weather, and dark composite doors that sit in full sun expand more. On a hot afternoon a door that fitted its frame in April can grow enough to bind at the top or lock side, so the hooks no longer meet the keeps and the handle becomes hard to lift. Cool it down and the fault disappears, which is why so many people say it only happens in summer.
Winter works the other way. The slab contracts, gaps open along the seals, draughts appear and a door that closed with a firm push now rattles. Neither is a fault in the mechanism. Modern flag hinges have adjustment for height, side-to-side movement and compression, and a locksmith can set the door so it locks cleanly through both extremes.
Gearbox failure and the locked-in risk
The gearbox wears a little every time the handle is lifted, and it wears faster if the door has been out of line for a while and the handle has been forced to compensate. When it finally fails, it tends to do so with the door closed and locked, because that is the moment of highest load. The hooks stay out, the handle no longer releases them, and the door cannot be opened from either side.
If that door is your only way out, or a child or pet is on the other side, treat it as an emergency and call the 24-hour lockout service. Do not lever the door open. A jammed multipoint door can still be released without damage by someone who knows the mechanism, but not by a crowbar.
What the locksmith does on site
The visit follows a set order, and most jobs are finished in one trip.
- Get the door open without damage. With the mechanism jammed, the locksmith removes the handles and cylinder, works the gearbox free from the door edge and releases the hooks, so the slab and frame are untouched.
- Identify the mechanism. Every multipoint strip carries a stamp on its faceplate. Fullex, Winkhaus, Yale, Maco, GU and ERA are among the most common makes, and each has several gearbox patterns that differ by backset, spindle position and the distance between handle and keyhole.
- Replace only the gearbox. In most cases the hooks, rods and faceplate are fine. The old gearbox is unscrewed from the centre of the strip and a matching unit fitted in its place, so the door keeps its original locking points.
- Realign the door and adjust the keeps. The hinges are set so the slab sits square in the frame, and each keep is adjusted so the hooks enter without scraping. The lock is then tested with the door open, shut, and locked from both sides.
Full detail on the service, including the makes carried in the van, is on the uPVC door repair page.
Repair or new door: what it costs
The repair cost depends on which part has failed. These are the starting prices, confirmed as a fixed figure by phone before the locksmith sets off.
| Job | Starting price |
|---|---|
| Multipoint gearbox replacement | from £85 |
| Door alignment / adjustment | from £65 |
| Handle replacement | from £55 |
| Letterbox or hinge replacement | from £45 |
A replacement door only makes sense when the slab itself has failed: a crack through the panel, a warp so severe that adjustment cannot bring it back, or a frame that has split or rotted. A discontinued mechanism with no compatible gearbox is the other trigger, but that is unusual, since most obsolete patterns have a current equivalent. The pricing page carries every starting price across the site.
Composite doors
A composite door uses the same multipoint strip, gearbox and euro cylinder as a uPVC door, so every fault and fix above applies. Two differences matter. The slab is heavier, so hinge wear and drop tend to show sooner, and dark-coloured composites absorb more heat, so summer expansion is more pronounced. If you are having a new cylinder fitted anyway, an anti-snap one is worth the small extra cost; the residential locksmith page explains the TS007 star ratings.
Keeping the mechanism healthy
A multipoint lock will run for many years if it is not fought. Lift the handle all the way up before turning the key, and never turn the key against a handle that has only half-lifted. Do not slam the door; the hooks should be retracted when it closes. Lubricate with a dry spray in spring and autumn, tighten hinge screws when you notice movement, and book an alignment the first time locking becomes stiff rather than the tenth.
Open-in Security Services repairs multipoint doors across West London from its base in Ickenham, including Ruislip and Hillingdon. Call 07904 594452 with a description of what the door is doing and you will get a fixed price for the repair before anyone comes out.
FAQ
Upvc door won't lock: Quick Answers
Why won't my uPVC door lock when it is closed but locks fine when open?
The mechanism is working; the door is out of line. When it is shut, the hooks and rollers are missing the keeps in the frame, usually because the door has sagged on its hinges or the frame has shifted with the seasons. Adjusting the hinges and keeps normally fixes it, from £65.
My uPVC door handle has gone floppy. Is it the handle or the lock?
A handle that flops with no spring behind it usually means the spring cassette inside the handle or the gearbox spring has broken. If the door still locks with the handle lifted, a new handle from £55 may be all you need. If the handle no longer moves the hooks, the gearbox has failed and needs replacing from £85.
The key turns but my uPVC door won't open. What has happened?
The cylinder is fine; the multipoint gearbox behind the handle has failed and is no longer releasing the hooks, so the door stays locked from both sides. Do not force the handle. A locksmith can usually open the door without damage and fit a new gearbox in the same visit, from £85.
Can I spray oil on a uPVC door lock to free it up?
Better not. Penetrating and household oils attract dust and grit and turn to a sticky film inside the gearbox, which makes stiffness worse over time. Use a dry PTFE or silicone spray on the lock strip, hooks and keeps instead, once or twice a year, and wipe off any excess.
Do I need a new uPVC door if the lock has broken?
Rarely. Multipoint doors fail at the gearbox, the handle or the cylinder, and every one of those parts can be swapped while the slab and frame stay put. Budget from £85 for a gearbox and from £65 for realignment. Only a cracked or warped slab, or a damaged frame, justifies a new door.