Replacing a Euro Cylinder with Thumbturn in a Composite Door

[little_poppet]

I’m trying to replace the lock on my composite door. It has a multipoint mechanism with a euro cylinder and an internal thumbturn. I’ve run into a few issues:

On the outside there’s a circular escutcheon. On the inside I can twist the matching escutcheon off, but the external one won’t budge.

It doesn’t seem to twist off like the inside plate.
I can’t see any retaining screws from the inside holding it in place.
When I removed the interior plate, the tiny screws I found were just fixing into the door skin, not holding the cylinder.

On the inside, I can’t slide the escutcheon plate past the thumbturn. Maybe that isn’t necessary, but I wasn’t sure if there’s a way to detach the thumbturn knob so the plate can be removed.

So far, I've removed the long retaining screw on the edge of the door (the one that secures the cylinder in place).
I've turned the thumbturn to around 25° so the cam should line up.
At that point I was expecting the cylinder to slide out, but it’s stuck and won’t move.

Does the external escutcheon need to come off to release the cylinder?
Is there a trick to getting the thumbturn plate off from the inside?
Or is the cylinder just being pinched by the fittings/escutcheons and I need to wiggle/loosen more?
Any advice appreciated

 

[blup]

Try prying the cover off, protecting the surface of the door by levering against a sliver of wood or similar

 

[JohnD]

Show us the inside of the door please, behind the escutcheon

 

[little_poppet]

Show us the inside of the door please, behind the escutcheon

that's pic 2

 

[little_poppet]

Try prying the cover off, protecting the surface of the door by levering against a sliver of wood or similar

is this guesswork? i really only want to do this as a last resort unless it's definitely the case that this needs to be removed

 

[JohnD]

Some external escutcheons are fixed with retaining screws from the inside. This is common if they surround the external end if the cylinder to prevent it bring twisted off. But in your case I think it does protrude.

You could try an anaconda strap wrench if you can lay your hands on one. A rubber band round the escutcheon, or elastoplast, will give you more grip. But I have found that if the external trim is a push fit on a screwed backplate, any bend or dent in the trim makes it practically impossible to pull off. Corrosion between the two would do the same. I think you may end up having to slit it with a dremel.

 

[JohnD]

I would guess yours is something like this

 

[JohnD]

The internal plate on yours looks like it has a screw thread on it, so the decorative cover might be screwed on.

 

[blup]

is this guesswork? i really only want to do this as a last resort unless it's definitely the case that this needs to be removed

I would think the escutcheon is there to prevent or discourage snapping. You might be and to lever it off or twist it with grips

 

[little_poppet]

Show us the inside of the door please, behind the escutcheon

see "internal" pic

 

[little_poppet]

The internal plate on yours looks like it has a screw thread on it, so the decorative cover might be screwed on.

yeah on closer inspection the external plate had the same inner circle indicating a screw thread and i managed to screw it off. but still struggling to get the thumbturn lock out. the lock is a bit dodgy with the key sometimes turning without engaging the lock so it might not be shifting the cam, spent an hour trying to wriggle it out, will have to give it another go with a fresh mind

 

[@tlan]

Thumbturn should only be around 5-10 degree off vertical not 25. Put pressure on outside cylinder face while turning thumbturn and you should be able to get it lining up.

@tlan.

 

[JohnD]

yeah on closer inspection the external plate had the same inner circle indicating a screw thread and i managed to screw it off. but still struggling to get the thumbturn lock out. the lock is a bit dodgy with the key sometimes turning without engaging the lock so it might not be shifting the cam, spent an hour trying to wriggle it out, will have to give it another go with a fresh mind

I would have thought the cam might be turning but mechanism worn out, hence not engaging.