Most uPVC door problems come down to a few millimetres in the wrong place, and you can fix them with one Allen key.
The hinges adjust in three directions: up and down, side to side, and in and out towards the frame. Work out which direction your door needs to move, then turn the matching screw a quarter turn at a time. Ten minutes of small corrections usually beats a call-out.
Diagnose the symptom first, then pick the adjustment axis. Do not start unscrewing caps.
Flag hinges adjust in all three directions. Butt hinges offer the least movement.
A quarter turn at a time, then close the door and check. Repeat.
Stiff locking is often the keeps, not the hinges.
A door that touches top and bottom but gaps in the middle has bowed, and no adjustment fixes that.
Three things cover almost every job: a set of Allen keys (hex keys), a flat-head screwdriver for the plastic covers, and a torch. A cross-head screwdriver helps on the keeps. Most uPVC and composite door hinges take a 4mm or 5mm Allen key, so have both to hand.
Work with the door open where you can, and close it after every adjustment to check what changed. Adjusting blind is how a small misalignment becomes a big one.
One warning before you touch anything. If your door is under warranty and the problem appeared within weeks of installation, contact your supplier first. Adjusting it yourself is fine on a door that has settled over years. On a new door, a supplier visit costs you nothing and rules out an installation fault.
Most guides open by asking which hinges you have. That is the wrong first question, because you arrived here with a symptom. Find your symptom below, and it tells you which direction the door needs to move.
Write down which row matches before you go further. If two rows match, deal with the height first. Height errors create the gaps that look like compression problems.
Open the door and look at the hinge from the inside edge. The shape tells you the type, and the type tells you how much movement you have available.
Flag hinges are standard on most modern uPVC external doors, so that is the likely answer. If your door came with paperwork, the hinge model is usually listed there, and the manufacturer's own instructions will give you the exact screw positions.
Glas in der Haustür wirft beim Thema Sicherheit Fragen auf, denn eine Glasfläche könnte eingeschlagen werden. Auch hier gibt es gute Lösungen.
An gefährdeten Stellen, besonders wenn Glas in Reichweite des Schlosses sitzt, ist Sicherheitsglas sinnvoll. Verbundsicherheitsglas (VSG) besteht aus mehreren Scheiben mit einer reißfesten Folie, an der die Splitter bei Bruch haften, sodass kein durchgreifbares Loch entsteht.
So bleibt der Lichtgewinn erhalten, ohne dass das Glas zur Schwachstelle wird. Glas und Beschläge sollten dabei zusammen betrachtet werden. Unsere Türen entsprechen den aktuellen Anforderungen an die Sicherheit; mehr dazu im Ratgeber zum Sichern der Haustür.
A dropped door drags on the threshold, catches on the floor covering, or leaves a widening gap along the top edge. Weight and gravity do this over years, and it is the most common uPVC door fault in British homes.
Step 1. Open the door and prise off the plastic cap at the top of each hinge with a flat-head screwdriver. On some flag hinges the height screw sits at the bottom instead, so check both ends.
Step 2. Insert the Allen key into the height screw on the bottom hinge first. Turn clockwise to lift the door.
Step 3. Turn a quarter to a half turn, no more. Close the door. Check the drag.
Step 4. Repeat on the middle and top hinges by the same amount. All three hinges must carry the door together. Lifting one hinge and not the others puts the whole load on that hinge and it will fail.
Step 5. Once the drag has gone, open and close the door five or six times, then check again. Doors settle after adjustment.
If you run out of thread and the door still drags, stop. Either the frame has moved, or the door has dropped further than the hinges can correct.
Lateral adjustment moves the door left or right within the frame. Reach for it when the gap down one side is wider than the other, when the door scrapes on one edge, or when the lock points miss the keeps.
Find the horizontal screw on the side of the hinge body. On flag hinges you may need to remove a cover plate first, held by a single screw on the back of the hinge. Support the plate as you undo it so it does not drop.
Turning the screw moves the door towards or away from the hinge side. A quarter turn at a time, then close the door and look at the gap along both sides. You want the same gap top to bottom on the handle side.
Adjust all hinges by the same amount unless you are deliberately squaring the door. Uneven lateral adjustment twists the door leaf and creates draughts you will spend the next hour chasing.
Compression controls how hard the door presses against the frame gasket. Too little and cold air comes through.
Too much and the handle needs both hands, the gasket flattens, and the seal stops working within a couple of seasons.
Find the compression screw. On flag hinges it usually sits at the bottom of the hinge body, behind its own cap. Butt and rebate hinges adjust compression through the screws on the side of the hinge.
Here is the test that tells you when to stop. Take a sheet of paper, close the door on it, and pull. You want firm resistance without tearing, and you want the same resistance at the top, middle and bottom of the door.
Tug-of-war on one corner and a paper that slides free on another means the door is out of square, not under-compressed.
Two seasonal notes worth knowing. uPVC expands in summer heat, so a door that seals well in January can bind in July. And a draught that appears only in wind is often the gasket itself perishing rather than the compression setting. Run your finger along the rubber. If it feels hard and shiny rather than soft, replacing the gasket solves what no hinge adjustment can.
This is where most DIY attempts go wrong. Your door lifts fine on the handle, but the key will not turn. You adjust every hinge you can find. Nothing changes.
The lock on a uPVC door throws hooks, rollers or bolts into metal plates on the frame called keeps or strike plates. If those hooks do not line up with the keeps, the mechanism cannot complete its travel, and the door was never the problem.
Look at the keeps with the door open. Most have slotted screw holes, which means they move. Some have a small cam or grub screw that adjusts the depth the hook engages to. Loosen the fixing screws, shift the keep two or three millimetres in the direction the hook needs, and retighten.
Check the marks on the keeps before you start. Bright scrape lines on the metal show you exactly where the hook is hitting and which way to move. That evidence beats guesswork.
If the mechanism itself feels gritty or the handle springs back without throwing the hooks, the gearbox is worn. That is a replacement part, not an adjustment.
Some doors drop at the front corner while the hinge side stays put. The gap opens along the top of the handle side, and lifting all three hinges evenly does not close it.
The fix uses lateral adjustment to create a squaring effect. Move the top hinge back towards the frame, and the bottom hinge forward towards the opening side. The door pivots on the middle hinge and the leading top corner rises.
Two millimetres at each end is plenty. Then check every edge for new gaps, because squaring a door in one place opens it up in another. Water ingress and draughts follow gaps, so do not accept one to fix the other.
If you cannot get the door square without opening a gap somewhere, the frame has moved. That is a fitting question rather than a hinge question.
Some faults sit outside what an Allen key can reach. Recognising them saves you an afternoon.
The bowed-door case is the one worth knowing about before you buy.
It happens most on dark-coloured doors in strong sun, and it is one reason our composite front doors are supplied on a solid timber frame, and why door construction matters more than the colour swatch when you order.
