Any lock experts? Key sticking in lock

[aargh]

Hi, we have had this problem twice now with our (internal) front door so am wondering if there is anything else we can try?

It is a uPVC door, with an Avocet strip lock (9235, 4-hook/roller) - the type where you have to push the handle up vertically before turning the key to lock it.

Twice now, when the door was being locked, the key has become stuck (in the unlocked position) so it was impossible to turn or remove the key. So the door was unlocked and could be opened, but could not be locked, and the key was stuck fast.

We tried WD40, lots of wiggling, pushing in the bit round the key while pulling the key, etc etc but nothing helped. Eventually had to call a locksmith, who took it all apart, had to snap the cylinder to get it out, but couldn't find the reason for the problem so could only replace the cylinder with a new one. This obviously didn't help though, as we then had the same problem a month or two later with the new cylinder. He could only suggest if it happens again replacing the whole lock.

I am hoping it won't happen again, but if it does, is there anything else we can try before having to pay ££ for a new strip? Has anyone else had this problem before?

Thank you!

 

[JohnD]

you can try lubricating the key with graphite dist before you insert it. This leaves a dry lubricating film that (unlike oil) does not attract dirt and grit.

Avocet is a low-priced maker but usually of reasonable quality.

Are you using copy keys or does it happen with the original manufacturer's key?

What do you know about the locksmith's experience and qualifications? There is a scam around where incompetent people advertise themselves as on-call locksmiths, and will spend typically an hour pretending to work on your lock (at your expense), before announcing that it can't be opened and will have to be forced.

 

[foxhole]

Check securing screw for barrel is tight [and not missing] as if the barrel can move even a 1mm it can bind.

 

[aargh]

Thanks!

Re the keys - I don't know whether the one involved the first time was an original or a copy, as far as I remember it was one of those we were given by the previous owners when we moved in, but not sure whether it was a copy they had made or an original.

When it happened the second time though, it was with the new cylinder and I think it was with one of the keys that came with that (i.e. original). Can't be absolutely sure though as we did get one or two copies made, and the locksmith threw out the stuck one so I couldn't check whether it was one of those.

Re the locksmith, I don't know about his qualifications but we chose him as the company was recommended on Which? local (which you have to be signed up and paying to be on I believe). They were also recommended somewhere else that I looked too, though I can't remember where. He did manage to replace the cylinder both times, and seemed to know about the lock and got us a quote for replacing the strip, so he wasn't obviously incompetent.

 

[aargh]

Thanks again - cross posted! Where would the securing screw be? Is the barrel the same as the cylinder? The only screws visible once it's put back together are two securing the inside doorhandle panel, and the ones down the lock strip holding it onto the door.

 

[foxhole]

There is a securing screw behind the plate at the edge of the door , locks into the centre of the cylinder.