I hope someone can advise me on this problem.
We have a double-glazed front door (metal frame covered with PVC or similar, i.e. not a wooden door) with an integral lock that works like this: normally, when the door is not locked, you still need the key to get in from outside, but inside you can just use the handle (with a lever like an internal door) to open it. If you lock the door, there are locking points along the side of the door opposite the hinges, with 'hook' shaped catches that engage with the metal holes in the frame. Then when locked, you need to use the key to open the door from either side. That's how it should work (hope that all makes sense).
Anyway, I've introduced a problem. At the weekend I was cleaning around the door frame which had got dusty and dirty over the years, and I noticed that several screws were not tight so I tightened them up. Since I did this, I can no longer lock the door as described above - if I try to turn the key it won't turn all the way round. I loosened some of the screws in the door itself and I can just about turn the key now with difficulty, but my wife can't manage to lock it, so she has to leave it unlocked. Of course nobody can just open the door and walk in, but I don't like leaving it like this for security reasons.
I've obviously introduced this problem myself. It seems that having loose screws must be an essential part of the adjustment - I foolishly thought they had worked loose over the years.
I now wonder if the hinges can be adjusted to get the door right - I also tightened up some screws on the hinges that seemed loose, but maybe these were meant to be adjusted to get the door to hang properly. This seems to me to be the most likely adjustment it needs but I'm not sure.
Any suggestions would be welcome. I feel a bit of a dipstick now and wish I'd never touched the bloomin' thing! :(
The door is too old to be able to call anyone in under a warranty so if I can sort it myself I'd prefer to do that.
Thanks for any help.
Flummoxed