How do I adjust the keeps on a uPVC door?

Setting compression at the keeps so the door seals without straining the gearbox, and why this must come after the hinges rather than before.

Difficulty: beginner
Time: 45 min
Read: 3 min

Short answer

Square the door with the hinges first. Then turn each keep's cam or eccentric a small amount towards the outside to increase compression, testing after each one — the door should need a firm but easy lift to lock.

The keeps are the metal plates on the frame that the hooks and rollers of a multipoint lock engage. Most have an adjustment that sets how hard the door is squeezed onto its seal, and it is the last adjustment you make, not the first.

What you'll need

An Allen key set
A Torx driver, on some systems
A flat screwdriver
A strip of paper for testing

The three adjustment points on a uPVC or composite door

Step by step

Fix the alignment before the compression.If the door is not square in the frame, tightening the keeps just forces the hooks into misaligned plates and wears the gearbox. Hinges first, always.
Map where the draught is.Close the door on a strip of paper at the top, middle and bottom of the lock side. Where it slides out freely, that keep needs more compression.
Identify the adjustment type.Most keeps have either a small cam turned with an Allen key or Torx bit, or an eccentric plate held by two slotted screws. Some cheaper systems have neither and only adjust by moving the whole keep.
Work one keep at a time.Adjust, close the door, test. Doing all of them at once means you cannot tell which change did what, and it is easy to overdo the total compression.
Make small movements.A quarter turn on a cam is a lot. The whole useful range is usually under 2mm.
Judge by the lift-and-lock feel.Lifting the handle should meet firm, even resistance and then throw cleanly. If you are leaning on it, the compression is too high and the gearbox is being loaded every time.
Move the whole keep for a vertical error.If a hook is meeting the plate high or low rather than being loose, slacken the keep's fixing screws and slide it in the slotted holes.
Deal with the head and threshold separately.Top and bottom shootbolts usually have their own keeps with their own adjustment. A draught at the very top of a door is almost always the head keep.
Retest in the cold.uPVC and composite doors move seasonally. Set the compression in mild weather and expect to check it once after the first hard frost.

Tips

Mark the original position of each cam with a pencil dot before turning it. It makes going back trivial.
A door that needs a hard shove to lock is not secure — it is a gearbox failure waiting to happen. Reduce compression and fix the alignment instead.
Test the door from both sides. A keep that seals against a paper strip from inside can still be leaving a gap visible from outside.

Common mistakes

Winding the keeps in to cure a draught caused by a flattened gasket — It works for a season, then the extra load fatigues the gearbox, which is a far more expensive part than a length of gasket. If the seal has taken a permanent set, replace the seal.
Adjusting the keeps before the hinges — Moving the hinges afterwards changes where every hook meets its keep, so all the keep adjustment has to be redone. The order is fixed for a reason.

If it doesn't work

Door seals at the middle but draughty at the top

Cause: Head keep under-compressed — Fix: Adjust the top keep or shootbolt keep only.

Handle very hard to lift

Cause: Total compression too high, or door dropped — Fix: Back the keeps off a little and check the door is square first.

Hook grinds as it enters the keep

Cause: Keep too high or too low — Fix: Slacken the keep screws and move it in the slots until the hook enters cleanly.

Adjustment made no difference

Cause: Keeps with no cam adjustment — Fix: Move the whole keep outward with packing behind it, or replace with an adjustable keep.

Questions people ask

How do I know if it is the hinge or the keep?

A misaligned door rubs, grinds or needs lifting. An under-compressed door closes easily and still lets air through. Rubbing is hinges; draught with easy closing is keeps.

How much compression is right?

Enough that a paper strip is gripped all round and the handle lifts firmly without effort. Both extremes cause problems — too little draughts, too much destroys gearboxes.