The most occurring event when uPVC door needs adjustment is that when you go to lift the handle up and it seems "stiff". If this is happening you need to make proper adjustments with your uPVC door or call in an expert.
If you continue to carry on using the lock there is a very good chance the lock will fail and the worse case scenario, it can fail in the locked position when you’re outside. This will mean getting a locksmith to not only get you in but also most likely change the whole locking mechanism, which will be inevitable an expensive affair.
You can adjust the PVC, PVCu, uPVC door by first opening the door and try to lock the door in the open position, if it works fine then the problem is with the keeps and the lock is fine.
I was lurking on this post as I have a similar question. The door handle in my garage fire door has come out. The builders who installed it have put in long screws as the clearly did not think it would hold.
The door's core is indeed some sort of particle board similar to chipboard but I guess treated to increase fire resistance. I assume my problem comes from the force on a door handle being greater than a hook. I wonder which of the following options would be best?
1) Use a fatter screw (not ideal as it won't suit the door handle)
2) Use some sort of glue on the thread (It would have to be weak enough should the handle ever require removed again.
3) Add some sort of filler or plug to the hole and screw into it. (If this option what would be the best plug?