How to change a lock cylinder in 10 minutes (reinforced doors too)

What you need

• Phillips or flat screwdriver, depending on the faceplate screw
• Callipers or a tape measure to measure the old cylinder
• Torx key if the security escutcheon uses Torx screws (on some reinforced doors)
• New cylinder with the same measurements: Tesa TE5, Abus D6, Ezcurra DS15, Mottura Champions, Yale (Leroy Merlin, Bricodepot, ferretería)
• Powdered graphite lubricant
• Spare M5 faceplate screw, in case the original is damaged (usually comes with the cylinder)

Step by step

1. 1

   Measure the old cylinder or the door

   Before buying, measure the cylinder you are removing: overall length and the position of the screw (the centre of the cam), which is almost never in the middle. A 30/40 cylinder is 70 mm long with the cam 30 mm from one side and 40 mm from the other. If you do not want to take it out first, measure the thickness of the door plus the escutcheons on each side. We explain it in detail in how to measure a lock cylinder.

2. 2

   Open the door and wedge it

   Never change a cylinder with the door closed. Open it, put a wedge or a cloth under it so it does not move and make sure you have the new key to hand before removing the old one.

3. 3

   Loosen the faceplate screw

   On the edge of the door, on the metal faceplate of the lock, there are several screws. The cylinder screw is exactly level with the cylinder, below the bolt. Take it right out and keep it safe.

4. 4

   Align the cam and pull the cylinder out

   Insert the key in the cylinder and turn it slowly 15-20 degrees one way or the other. You will feel the point at which the cam (the part that turns and moves the bolt) tucks inside the cylinder body. At that point, pull the key towards you with the cylinder. If it does not come out, move the key slightly left and right until you find the position.

5. 5

   On a reinforced door: check the escutcheon

   If the door is reinforced with a security escutcheon, the escutcheon may be holding the cylinder. Check whether the escutcheon has a fixing screw at the bottom or whether it has to be removed from inside (two long screws on the inner face). If the escutcheon is the closed type and the cylinder does not protrude, the replacement has to be exactly the same length so it neither sticks out nor sits recessed.

6. 6

   Insert the new cylinder

   Put the key in the new cylinder, turn until the cam is tucked in and push it into the hole, with the correct length side facing out. If the cylinder is 30/40, the 40 side goes towards the thicker escutcheon. Turn the key a little until you feel the screw hole line up.

7. 7

   Tighten the screw and test

   Screw in the faceplate screw until firm, without tightening fully: an overtightened screw distorts the cylinder and the key becomes stiff. Turn the key both ways with the door open. The bolt should go in and out smoothly. Then close the door and test from outside and inside.

8. 8

   Lubricate and keep the keys safe

   Put powdered graphite in both keyways of the cylinder. If the cylinder comes with an ownership card (anti-bump and security ones do), keep it: you will need it to get copies cut. The keys from the old cylinder are no use now; throw them away or keep them labelled.

When the cylinder needs changing and which cylinder to choose

Change the cylinder when you move into a new or rented home (you do not know how many copies are in circulation), when you have lost the keys, when the key goes in badly or turns stiffly even after lubricating, when the cylinder protrudes more than 3 mm on the outside (it makes break-ins by snapping the cylinder easier), or when you want protection against bumping.

The builder's cylinder fitted to most flat doors in Valencia and Alicante is a standard series with no protection at all. A mid-range anti-bump, anti-snap cylinder (Tesa TE5, Abus D6, Ezcurra DS15) costs 35-70 euros and opens just as easily with the key but far less easily without it. For reinforced doors, a high-end one (Mottura Champions, Abus EC, Tesa TX80) costs 90-200 euros and is combined with a security escutcheon.

Always buy one with an ownership card: copies are cut with the card and nobody can duplicate the key at a key-cutting stall.

Common mistakes when changing a cylinder

• Buying by overall length without checking the offset. A 35/35 and a 30/40 are the same length (70 mm) but the screw does not line up on one of them. Without the correct offset, the cylinder will not hold.
• Forcing the cylinder out. If it will not come out, the cam is not aligned. Do not lever it: turn the key a little more until you find the point.
• Leaving the cylinder protruding on the outside. More than 3 mm beyond the escutcheon is an invitation to snap it with a pipe wrench. Choose the size that sits flush with the escutcheon.
• Tightening the faceplate screw fully. The key becomes stiff and within weeks it snaps inside.
• Losing the ownership card. Without it there are no copies for security cylinders.
• Drilling the old cylinder because it will not come out. Never on a reinforced door: the escutcheon has anti-drill plates and the door can be left unusable. On any door, a locksmith gets it out without drilling.

When to call a professional

Changing the cylinder on an ordinary flat door is the easiest job on this website. It stops being easy when the security escutcheon is the type fixed from inside that covers the cylinder (Disec, Mottura, Tesa escutcheons with magnetic protection), when the door is armoured with a lever lock (a lever cylinder, not a Europrofile), or when the cylinder has broken inside and the cam will not turn.

At Manitas Costa changing a cylinder costs 40-60 euros labour; the anti-bump cylinder from 35 euros, and we show it to you before fitting it. We carry the most common sizes in the van, so it is usually sorted in a single visit. Fixed price by WhatsApp with a photo of the door edge.

More information in locksmith in Valencia, Alicante and the Costa Blanca and in how much it costs to change a lock and a cylinder. If it is the bolt that is not working rather than the cylinder, see how to change a door lock.

Safety: never drill a reinforced door

We repeat it because every month a door like this comes our way. A reinforced door has a steel escutcheon with anti-drill plates designed to destroy drill bits. If you try to drill the cylinder, the usual outcome is that you break two or three bits, damage the escutcheon and leave the cylinder half turned and jammed. From there, the opening is more expensive and sometimes the whole escutcheon has to be replaced, which costs 40-120 euros plus fitting.

If the cylinder on a reinforced door will not come out, the reason is almost always one of these: the faceplate screw is not fully out, the escutcheon has a bottom fixing screw, or the cam is not aligned. Check all three before doing anything.

On the coast, choose nickel-plated cylinders or ones with an anti-corrosion finish and lubricate with graphite every 6 months. On the seafront, in Torrevieja or Benidorm, an untreated cylinder seizes within a few years because of the salt air. We cover it in jammed lock: the cylinder will not turn.