How to adjust a uPVC door that has dropped, catches or won't lock

Every uPVC door drops a little over the years. The door is heavy, the hinges carry all of it on one side, and one day you notice you have to lift the handle hard to lock it, or the bottom corner scuffs the threshold. Caught early, that is a ten-minute adjustment. Left too long, it breaks the lock.

The short answer

Most uPVC doors are adjusted at the hinges. Each hinge has small adjusters, usually behind a cover cap, that move the door up and down (height), towards the hinge or the lock side (lateral), and in and out against the seals (compression). Raise the door with the height adjusters, centre it with the lateral ones, then fine-tune the keeps on the frame if the lock is still stiff.

The warning signs

• You have to lift the handle further than you used to before it will lock.
• The key is stiff or needs the door pushed or pulled to turn.
• The bottom corner on the lock side scrapes the threshold or leaves a mark.
• You can see daylight, or feel a draught, at the top corner on the lock side.
• The gap round the door is wider at the top than at the bottom.

Step 1: check the gaps

Close the door and look at the gap between door and frame all round, inside and out. A properly hung door has an even gap, roughly the same along the top and down both sides. Use a coin as a feeler if it helps.

• Gap wide at the top on the lock side, tight at the bottom: the door has dropped. Raise it (Step 3).
• Rubbing on the lock side along its length: move it towards the hinges (Step 4).
• Even gaps but draughty: it needs more compression or new gasket (Step 5).

Step 2: identify your hinges

Open the door and look at the hinges. There are two common kinds:

Hinge type	How it looks	Where the adjusters are
Flag hinge	A flat leaf on the frame and a barrel, with a plastic cover cap	Under the cap; usually a hex key for height on top and a screw on the side
Butt hinge	Two leaves either side of a knuckle, often with plastic caps on top and bottom	Through the knuckle caps, usually with a hex key

Most need a 4mm or 5mm hex key and a cross-head screwdriver. If the hinges are painted over or have no adjusters at all, stop here and call: some older and budget doors can only be re-packed, which is glazier work.

Step 3: raise the door

1. Open the door and support its weight on the lock side with your foot or a wedge under the bottom corner.
2. Find the height adjuster on the top hinge first, then the others.
3. Turn each one a quarter turn in the same direction, by the same amount.
4. Close the door and check the gap. Repeat until the top gap is even and the handle lifts without force.

The top hinge carries most of the weight, so most of the movement comes from there.

Step 4: centre the door

If the door rubs along the lock side, use the lateral adjusters to pull it towards the hinges, again a little at a time on every hinge. If it rubs at the top only, move the top hinge more than the bottom.

Step 5: compression and draughts

Compression sets how tightly the door pulls onto its seals when locked. Too loose lets in draughts and rain; too tight makes the lock stiff. On the lock side, the keeps on the frame often have their own adjusters. Move them a millimetre at a time towards the outside to pull the door in tighter, then test with a sheet of paper closed in the door: it should drag, not slide out freely.

Step 6: test the lock

With the door open, lift the handle and turn the key. Everything should move smoothly. Close the door and do the same: it should take the same effort. If it is still stiff, the hooks are not quite meeting the keeps. Loosen the keep screws, slide each keep by a millimetre or two, and tighten.

Worth knowing: a light spray of silicone or light oil into the lock's moving parts along the door edge once a year keeps it running easily. Keep it off the gaskets and wipe off any extra.

When to stop and call

Stop adjusting and call a glazier if:

• the handle is floppy, or lifts but does not throw the hooks with the door open, which means a failed gearbox;
• the key will not turn at all, or you are locked out;
• the hinges are bent, cracked, or pulling away from the frame;
• the door rubs even after the adjusters have reached their limit;
• the door glass has misted or cracked.

Our uPVC door repair service re-hangs dropped doors and replaces multipoint locks, gearboxes and hinges across Central and North London, 24/7. Send a short video on WhatsApp of the door closing and the handle lifting: it usually tells us exactly which part has gone. If the door will not lock tonight, ring 07915 903485.

Windows drop in the same way. If yours catch or will not lock, see how to fix a uPVC window that won't close. And if it is time for a new door instead, our uPVC doors and composite front doors pages explain the options.