UPVC door lock barrel

[gordon34]

Can anyone advise me please. My upvc front door lock can be locked with a key both inside and out. The problem is that if you leave the key in the lock on the inside and go out, pulling the door closed behind you, you cannot then get back in even with another key. This has happened to my wife on two occasions costing £90 + for a locksmith to unlock the door with a long piece of plastic on the most recent occasion.
The locksmith suggested that the lock barrel be changed for one that has a knob on the inside and a keyhole on the outside only.
My questions are: 1. Is this a job that someone reasonably practical can do and if so 2. How does one go about identifying the specific barrel for the particular lock?
Any help please?

 

[garyo]

Yes, this is very easy. Set the door in to the unlocked position, open your door and look at the latch/bolt area of the lock. There'll be a single screw that holds the lock barrel in place. Remove the screw and the lock will slide out.

Locks are measured by their inner/outer depth - e.g. this one on screwfix is 40mm / 55mm :

http://www.screwfix.com/p/yale-anti...humbturn-lock-40-55-90mm-brushed-nickel/27333

Measure your existing barrel to work out what you're after.

Gary

 

[gregers]

or get a slightly longer barrel and keep it as a key only on both sides.
trouble with a thumb turn on the inside is if anyone finds out they can smash a hole and turn the lock and gain entry.i have this problem on my sliding rear door,but my front door is the opposite,key both ways.

 

[gordon34]

Thank you garyo and gregers for your suggestions. I am not too worried about the door glass being broken and the knob being turned as we also have a small lobby with its own door which we usually keep locked both day and night. However my wife insists on locking the problem door at night also which I guess a thumb turn would rule out. I am not sure how the longer barrel idea works. Does it simply ensure that two keys can be fully inserted at the same time without the problem the existing barrel causes?

 

[gregers]

yes,this is what is fitted to my upvc front door.

 

[gordon34]

Thanks again gregers, I will think hard on your suggestion.