Jammed lock: the cylinder will not turn or the key will not go in

What you need

• Torch
• Thin flat screwdriver
• Precision tweezers
• Compressed air spray (Leroy Merlin, computer shops)
• Allen key or Phillips screwdriver for the cylinder screw
• Powdered graphite lubricant or WD-40 Specialist for locks (not 3-in-1 or oil)
• Clean cloth
• A new copy of the key, if the one you use is worn

Step by step

1. 1

   Check whether the problem is the door and not the lock

   Turn the key while pulling the handle towards you, then while pushing the door towards the frame. If it turns in either position, the lock is fine: the door has dropped and the bolt is rubbing on the keep. That is a hinge or strike plate adjustment, not a cylinder replacement.

2. 2

   Try another key

   A worn key or a bad copy can go in and not turn. Try the original key or another copy. If one turns and the other does not, the cylinder is fine and the key is the problem.

3. 3

   Look inside the cylinder

   With the torch, look into the keyway. If you see a piece of metal, paper or a toothpick, someone has pushed it in (it happens in communal entrance doors). Pull it out with the tweezers. If it is a piece of key, follow the guide to removing a broken key from a lock.

4. 4

   Blow out and lubricate

   A blast of compressed air removes dust and sand. Then powdered graphite or a short squirt of dry lock lubricant into the keyway. Push the key in and out 10 times without turning, to spread the lubricant over the pins.

5. 5

   Turn gently with small movements

   Push the key all the way in, press it slightly inwards and turn with little force, alternating small turns left and right. If you feel it give a little each time, keep going; the lubricant is getting in. Never use pliers or a spanner to turn: you will snap the key inside.

6. 6

   If the key will not go all the way in

   Take it out, look at it against the light and check it is not bent. Blow out the cylinder again. If it goes in halfway and always stops at the same point, a pin is corroded or seized. The lubricant can sometimes recover it; if not, the cylinder is replaced.

7. 7

   If it turns but the door will not open

   The cylinder works, but the cam is not moving the bolt or the lock mechanism is broken. That is a fault in the lock (the case), not the cylinder. It can be opened from inside if you have access, and the solution is to change the lock.

8. 8

   Replace the cylinder if everything else fails

   A corroded cylinder cannot be recovered. Loosen the screw on the lock faceplate, put the key in the open position, turn a few degrees to align the cam and pull out the cylinder. Measure the length, the offset and the type of cam, and buy the replacement. We detail it in how to change a lock cylinder.

Diagnosis: why a lock jams

A lock that jams suddenly usually has a simple cause. One that has been giving warnings for weeks (the key goes in worse each time, you have to jiggle it, it only turns in one position) is usually corrosion or wear. These are the cases we see most.

Common mistakes that break the cylinder

A jammed lock becomes a lock-out when it is forced. These are the things not to do.

• Turning the key with pliers or a spanner. The number one cause of a key snapped inside. The key gives before the pins do.
• Using 3-in-1 oil, olive oil or petroleum jelly. It lubricates for a day and the next day the dust sticks and forms a paste. Dry lubricant only: graphite or a specific lock lubricant.
• Spraying ordinary WD-40 generously. Classic WD-40 is a degreaser, not a long-lasting lubricant. It loosens the corrosion at the time but dries the cylinder out within days. Use the Specialist version for locks or graphite.
• Hitting the lock. It misaligns the cylinder with the cam and the lock stays blocked even with the right key.
• Drilling a reinforced or armoured door. Never do this yourself. The security escutcheon has hardened steel plates designed to destroy drill bits, and a badly drilled reinforced door is no longer secure and has no cheap fix. A locksmith opens it without damage.

When to call a professional

If the key will not turn after lubricating and trying another copy, or if it turns freely with no resistance, the cylinder is broken inside. If you are outside and the door is shut, do not keep trying for more than five minutes: every attempt makes the opening harder.

Our prices in Valencia, Alicante, Torrevieja, Benidorm and the rest of the Costa Blanca: opening a slammed door 60-90 euros from 8:00 to 21:00, cylinder replacement 40-60 euros labour (anti-bump cylinder from 35 euros), complete lock replacement 80-150 euros plus the lock. Fixed price before we start, 6 months written guarantee and an invoice.

More detail in locksmith in Valencia, Alicante and the Costa Blanca and in how much a locksmith charges in 2026. If the lock works but the door rubs and that is why the bolt will not go in, it is a job for a carpenter and costs 40-70 euros.

• The key turns freely or stops halfway after lubricating.
• It is a reinforced or armoured door or one with a security escutcheon.
• You are outside and the door is shut.
• You have already forced the key or the lock with tools.
• It is the door of business premises or a communal entrance with a master-keyed security lock.

Tips for the coast: salt air, sand and holiday homes

On the seafront in Torrevieja, La Mata, Benidorm or Jávea, an ordinary brass cylinder corrodes in 3-5 years. The salt comes in on the breeze and crystallises on the pins. The symptoms appear in spring, when the house is used again after the winter.

What works: lubricate every 6 months with graphite, buy cylinders with an anti-corrosion or nickel finish (Tesa TE5, Abus D6 and Ezcurra DS15 have finishes that hold up better), and fit a security escutcheon, which also covers the cylinder opening and keeps the salt out.

If the property is a holiday home, ask whoever keeps an eye on it to put the key in and turn it once a month. And leave a copy of the key with someone you trust in the area: an opening on a Sunday night costs 90-150 euros and a set of copies costs under 20 euros.