"Replace the lock" on a UPVC door can mean three very different jobs. Knowing which part has failed saves money and avoids replacing parts that still work. If your door won't lock or open right now, see UPVC door lock repair for urgent help.
The three parts of a UPVC door lock
The cylinder (euro cylinder) is the part you put the key into. It's the cheapest part to replace and the part burglars attack by snapping.
The gearbox and multipoint mechanism run down the edge of the door. Lifting the handle throws hooks, rollers or bolts into the frame at several points; the gearbox in the middle drives them.
The handles operate the gearbox. A handle can feel loose because its own spring has gone — or because the gearbox behind it has failed.
Signs each part needs replacing
Cylinder: key stiff, hard to insert, won't turn fully, a snapped key, lost keys, or you want an anti-snap upgrade.
Gearbox / multipoint: handle floppy or won't lift, key turns but nothing locks, door locks but won't unlock, or grinding inside the door edge.
Handles: cracked, loose on their fixings or drooping, while the lock itself works normally when the handle is held up.
When a repair is enough
Many UPVC lock problems are actually alignment problems. If the door has dropped, the hooks and rollers grind against the keeps and the lock feels like it's failing. Adjusting the hinges and keeps may solve it without new parts — and if a part does need replacing, the alignment has to be corrected too, or the new part will wear out early.
What we check before replacing anything
How the door sits in the frame and whether the hinges need adjusting.
The make, backset and centres of the multipoint lock, so any replacement is a correct match.
The cylinder size and rating — and whether an anti-snap upgrade is worthwhile.
We then explain what's failed and agree the price with you before fitting anything. Common parts can often be replaced on the same visit; if your lock needs a less common part, we'll tell you and arrange a return visit.
Upgrading while you replace
If the cylinder is being replaced, it's the right moment to fit a TS007 3-star or Sold Secure Diamond anti-snap cylinder. Our anti-snap lock comparison explains the differences between Ultion, ABS and Yale.