Doors, windows & security
uPVC door won’t lock? It’s probably alignment
When a uPVC door will only lock with a lift, a shove and some commitment, the lock itself is usually fine. The door has drooped a few millimetres, the multipoint hooks are missing their keeps, and every forced lift pushes the gearbox closer to failure. Alignment is the fix, and it is often a ten-minute one.
By the Tickover team · Published 1 June 2026 · 4 min read
How a multipoint lock actually works
Lift the handle on a uPVC or composite door and a strip of hooks, rollers or bolts rises along the door edge into keeps set in the frame; the key then deadlocks the lot. It is a good system with one weakness: it only works when door and frame line up within a few millimetres. Doors are heavy, hinges settle and uPVC moves with temperature, so the alignment drifts.
The lift-and-turn test
Open the door so it hangs free of the frame, lift the handle and turn the key. If everything moves smoothly with the door open but fights you when it is closed, the mechanism is healthy and the door is out of line. If the handle is stiff, gritty or floppy even with the door open, the gearbox itself is wearing out, and no amount of hinge adjustment will save it.
What is actually failing?
How urgent is this?
Fix this week; today if it will not lock
Drifting alignment gets worse until the gearbox pays for it. A door that cannot lock at all leaves the house effectively unsecured, which insurers take seriously: that one is an emergency locksmith job, not a diary entry.
The hinge tweak
Most uPVC doors hang on adjustable flag hinges, and a couple of quarter turns is often the whole repair. You need the right size Allen key, some patience, and a note of where you started.
Adjust the hinges without making it worse
Mark and photograph the starting positions
A marker dot on each hinge and a photo mean you can always get back to the original setting.
Find the adjustment points
Pop the plastic covers off each hinge. Flag hinges usually offer sideways, height and compression screws.
Quarter turns, one hinge at a time
Nudge the door towards the hinge side or lift it a fraction, matching wherever the hooks are catching.
Test with the lift-and-turn after every change
Close the door gently and feel the handle. You are done when it lifts without persuasion.
Colour the hooks if you cannot find the rub
Chalk or lipstick on the hooks marks the keeps they strike. Keeps can be eased a millimetre too.
One rule protects the gearbox while you work: never force the handle. If it needs real muscle, the door is telling you where the problem is, and the gearbox is the part that snaps first. They fail shut as often as open, which is how people end up locked inside their own hallway.
What the fixes cost
If hinge adjustment runs out of travel, the keeps need repositioning, or the handle has gone floppy, hand it over. Locksmiths and double-glazing engineers do this daily and can usually match even an obsolete gearbox. As a guide:
Adjustment vs gearbox
Locksmith alignment visit
often the minimum charge
Multipoint gearbox replaced
part price varies by brand
New cylinder if worn
Typical UK ranges, mid-2026, as a guide only. Your home, your area and the job itself all move the number — always compare real quotes.
While the toolkit is out, stiff locks and sticking doors covers the timber-door equivalents, and the security walk-round explains the lock standards worth upgrading to while a locksmith is already on site. If the same door’s glass has fogged up, the sealed unit can be replaced without touching the frame. And a door that only locks with a knack has no place on the pre-holiday checklist: fix it before you travel, not after.
Not sure what you’re dealing with?
Describe what the door is doing and Tickover Self-Diagnose will tell you whether it is a hinge tweak or a gearbox job, and can put it in front of vetted local locksmiths.
Quick answers
Why will my uPVC door not lock unless I lift it?
The door has dropped or shifted so the multipoint hooks no longer meet their keeps in the frame; lifting the door by the handle temporarily re-aligns them. Hinge adjustment with an Allen key usually cures it. Work in quarter turns, test after each change, and stop forcing the handle in the meantime, because sustained force is what kills the gearbox.
Can I adjust uPVC door hinges myself?
Yes, if the hinges have adjustment screws, which most modern flag hinges do. Photograph the starting positions, remove the hinge covers, and make quarter-turn adjustments one hinge at a time, testing the handle with the door closed after each change. If you run out of adjustment travel or nothing improves, the keeps need repositioning, which is a sensible locksmith visit.
How much does a uPVC gearbox replacement cost?
As a guide, expect £120 to £280 fitted, depending on the brand and how easily a matching gearbox can be sourced, against £60 to £120 for a basic alignment visit. Acting early matters: an adjusted door costs a fraction of a seized mechanism, and a gearbox that fails with the door locked shut adds forced-entry work to the bill.
Does a door that will not lock affect home insurance?
It can. Policies commonly require final-exit doors to be locked when the home is empty, and some specify the lock standard. A door that physically cannot lock may leave you unable to meet those conditions, which insurers can use to reduce or refuse a theft claim. Treat an unlockable external door as urgent and use another secured exit in the meantime.
This guide is general information for UK homes, not advice about your specific property. Anything involving gas must be done by a Gas Safe registered engineer, and notifiable electrical work by a qualified electrician. If you smell gas, call the National Gas Emergency line on 0800 111 999. If you’re ever unsure, stop and get a professional in — that’s exactly what Tickover is for.
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