Lock won't close anymore: diagnosis and fixes before calling a locksmith
First: identify the failure type
"Lock won't close" covers 4 distinct situations, and the fix changes for each. Watch what actually happens when you turn the key or handle.
Case 1 — Key spins freely
Key turns 360° without engaging anything. It's almost always a broken key bit trapped inside the cylinder, or a failed multi-point cylinder connector. Fix: remove the cylinder (central screw below the bolt), inspect the drive mechanism.
Case 2 — Bolt won't extend / retract
If the bolt stays stuck, the cause is usually mechanical: broken internal spring, misaligned strike plate, or a door that has shifted (wood swelling in winter, warped frame). Quick test: with the door open, work the handle — if the bolt extends normally, the strike plate is misaligned. If not, it's the lock.
Case 3 — Handle is floppy or doesn't spring back
Drooping handle, spins with no resistance: the handle spring (spindle/follower) has broken, or the fixing screw has loosened. Simple part to replace, €15-30 at a hardware store.
Case 4 — Key inserts but won't turn
See our guide broken key in the lock. Often a fouled cylinder (dust, old WD-40) or a worn deformed key.
Checks to run before calling
- Try a spare key — rules out the key-side problem
- Lubricate with graphite (never oil/WD-40) — fixes 30% of cases
- Tighten the handle and faceplate screws with a Phillips screwdriver
- Check bolt/strike alignment from the side, door open
When to call a locksmith
If the diagnosis above doesn't identify the cause, or if the door is locked (you're outside), call. In Brussels: 20-30 minute response time — see our 24/7 emergency. For cylinder replacement: our cylinders & locks page covers options and pricing.
What if I need a new lock?
Before buying a replacement at a hardware store, check three dimensions: (1) backset (centre-bolt to centre-cylinder distance, usually 72 or 70 mm), (2) faceplate type (size and shape of the metal strip on the door edge), (3) number of points (1, 3, 5). A lock that doesn't match these three won't fit.
