Three different faults look identical from the outside.
Broken or jammed lock
A key that turns without effect, a handle that has gone slack, a door that will not lock unless you lean on it — these feel like the same problem and are not. One is the cylinder, one is the lock body, and one is the door being out of alignment.
They cost very different amounts to put right, and the cheapest of the three is the one most often missed.
Which of the three is it?
The cylinder
The part your key goes into. When this fails, the key turns loosely without moving anything, jams halfway, or will not go in at all. It is the cheapest of the three to put right, because the cylinder comes out with a single screw and is a standard part.
The lock body
The mechanism inside the door edge, carrying the latch and the bolt. When this fails, the handle goes slack, the latch stops springing back, or the bolt no longer retracts. Replacing it means taking the door furniture off and drawing the lock out of the door — more work, and the part has to match the door.
The door itself
Often the real culprit, and the one nobody suspects. A door that has dropped on its hinges or swollen in damp weather forces the bolt against the strike plate instead of into it. The lock is then fine and the fix is adjustment, not replacement. If someone quotes you a new lock without checking the alignment, ask why.
How we work
Foto folgt
Wie Schloss defekt — dasselbe Motiv, englischer Alt-Text
- 1
We establish which of the three it is
From the outside all three feel similar, so we test rather than guess: does the key turn freely, does the handle move the latch, does the bolt travel its full distance with the door open. That takes a couple of minutes and decides everything that follows.
- 2
If you are locked out, we open first
A defective lock still has to be got past. Depending on the failure this is a normal opening, or it needs the cylinder removed — which is destructive to a part that is being replaced anyway.
- 3
Adjustment where adjustment is enough
A misaligned strike plate can often be moved a few millimetres, or a hinge adjusted. Where that solves it, that is what we do, and it costs a fraction of a replacement.
- 4
Replacement with a matching part
Cylinders come in standard sizes and we carry the common ones. Lock bodies vary far more — backset, spacing, forend dimensions — so if yours is unusual we may need to order it. In that case we make the door secure and closeable, and come back.
- 5
Multi-point locking
On front doors with several bolts driven by one turn, a failure is usually in the gearing or a connecting rod rather than the cylinder. These are manufacturer-specific parts, and honest work here means identifying the system and ordering the right one rather than forcing a generic replacement.
What will it cost?
A lock that is out of adjustment and a lock that has broken internally look identical from the outside and cost quite different amounts to put right.
Our calculator deliberately names no price for this. It covers the two door openings where we know in advance what is waiting for us; here the work depends on things nobody can establish over the phone.
So we do it the other way round: describe what you are looking at, and we name the price before anyone sets off. Parts are charged separately and only where something genuinely has to be replaced — an adjustment costs no parts at all.
Before it fails completely
- Never use oil or grease on a cylinder. It collects dust and becomes a paste. Use a lock spray with graphite or PTFE, and very little of it.
- Treat stiffness as a warning. A cylinder that is getting harder to turn will eventually snap a key, usually at the worst moment.
- If you have to lift or push the door to lock it, it is out of alignment. Fix that before it damages the mechanism.
- If you rent, report it in writing. A lock failing through wear is the landlord’s responsibility — but you need to have said so before.
Questions we are asked most
The key turns but nothing happens. What is wrong?
Usually the cylinder cam — the small tongue that transmits the turn to the lock — has sheared or come loose, so the key rotates without engaging anything. Occasionally it is the connection inside the lock body. Either way the door can normally still be opened without damage, and the repair is a replacement part rather than a new door.
The key is very stiff. Should I use oil?
Not oil, and definitely not on a cylinder. Oil and grease attract dust and turn into a paste that makes the mechanism worse within weeks — this is the most common self-inflicted lock failure there is. Use a dedicated lock spray with graphite or PTFE, sparingly. And take stiffness as a warning: a cylinder that is getting harder to turn is a cylinder that will snap a key.
The door only locks if I lift the handle hard. Is the lock broken?
Probably not. That is the classic sign of a door out of alignment — dropped on its hinges, or swollen with humidity — so the bolt is fighting the strike plate. The fix is adjusting the hinges or moving the strike plate. Left alone it does eventually damage the lock, because the mechanism is taking force it was not designed for.
Can you repair the lock, or does it have to be replaced?
Cylinders are not economically repairable — they are precision parts and a replacement costs less than the labour to rebuild one. Lock bodies sometimes are, if the failure is a spring or a fixing. Alignment problems are repairs by definition. We tell you which case yours is before doing anything, and if adjustment will fix it we say so rather than selling a part.
I rent. Who pays for this?
A lock that failed through normal wear is maintenance, and maintenance is the landlord's responsibility rather than yours. That changes if the damage was caused by use — a forced handle, a key broken through force. Two practical points: report a stiffening lock in writing before it fails, and keep the invoice, because you will need it either way.
Lock giving up on you?
Send us a photograph of it on WhatsApp — it often tells us more than a description.