Locks rarely fail without warning. A key that has started to stick, a handle that needs a hard lift, or a door you have to shoulder shut is the early stage of a fault — and dealing with it as a service is far cheaper than dealing with it as an emergency after the mechanism snaps or the key breaks in the lock.
Why locks fail — and why a service pays for itself
On uPVC and composite doors, the single most common cause of trouble is the door dropping a few millimetres on its hinges over time. Once it drops, the multipoint hooks and bolts no longer line up cleanly with their keeps, so you start lifting the handle harder and harder to force them home. That extra strain is loaded straight onto the gearbox — the heart of the mechanism — until one day it fails completely. Catching the alignment early is the difference between a quick adjustment and a full mechanism replacement plus a lockout.
The simple test that tells you it’s alignment
If your door locks perfectly when you hold it open but fights you when it’s shut, the lock itself is usually fine — it’s alignment. The door has dropped, or the keeps have shifted, so the bolts can’t find their homes. We adjust the hinges, reposition the keeps and free off the mechanism so it locks with a light touch again.
Seasonal sticking is normal — and adjustable
uPVC expands in heat and contracts in cold, so a door can press tight in summer and feel loose in winter. If yours works in some seasons but not others, that’s thermal movement, and we can set the compression and alignment so it works properly all year round.
What a lock service includes
- Check and adjust hinges and door alignment.
- Clean and correctly lubricate the mechanism and cylinder.
- Test every locking point, the latch and the handle return.
- Check and reposition keeps and strike plates.
- Inspect the cylinder for wear and snap resistance, and flag anything heading for failure.
Lubrication done properly
This is where a lot of self-help goes wrong. Use a dry PTFE or graphite lubricant in the cylinder and a light silicone spray on the moving mechanism parts. Never use WD-40 or general 3-in-1 oil: they break down, gum up and attract grit, and over time they shorten the life of the lock rather than extending it.
When to book
Book a service if the handle has gone loose or the key turns without throwing the bolts (a sign of a worn gearbox), if the key feels stiff or gritty, if you’re lifting hard or shouldering the door, if it sticks seasonally, or simply if it’s had years of use without any maintenance — gearboxes have a finite life, often around seven to eight years. We service homes, rental properties and businesses alike.