How to change a euro lock on a uPVC door

1. Confirm it is a euro cylinder

Most uPVC door locks use a euro profile cylinder. You will usually see the familiar key slot shape on the outside and often a key slot or thumbturn on the inside.

2. Remove the fixing screw first

Open the door and look at the edge of it, level with the cylinder. You should see one long screw holding the cylinder in place. Remove that screw and keep it safe.

3. Turn the key slightly to release the cam

Insert the key and turn it a little so the cam lines up with the cylinder body. Then slide the old cylinder out. If it feels tight, adjust the key angle gently rather than forcing it.

4. Measure the old cylinder properly

Measure from the centre screw hole to each end of the cylinder. That gives you the split size, for example 40/50.

Check this twice. A cylinder that sticks out too far can be more vulnerable, while one that is too short can be awkward to use.

5. Pick a better security cylinder where possible

For external doors, it is worth using an anti-snap, anti-drill, and anti-pick cylinder from a trusted brand. To be fair, lock quality matters more than shiny packaging.

6. Fit the new cylinder and test with door open

Insert the new cylinder, line up the cam with a slight key turn, and refit the long fixing screw. Test lock and unlock several times with the door open first.

7. Check operation with the door closed

Once it works smoothly open, close the door and test again. If it feels stiff only when closed, the issue may be alignment in the keeps or mechanism rather than the cylinder itself.

8. Matching locks around the house

If you want fewer keys, you can buy matching keyed-alike euro cylinders for back doors, side doors, garages, and some outbuildings where the lock type matches.

It depends on what hardware you already have, but it is often possible to get the same key working across several doors. That can make day-to-day access much easier.

When to call for help

Call Richard if the old cylinder will not come out, the multipoint mechanism feels rough, the door alignment is off, or you want all suitable locks around the house matched to one key setup.