Window lock?

you will need need handle only which comes as a set with the key, toolstation if do remember around £8

 

Do you mean the window only opens 5-7mm or the handle only moves 6-7mm?
If the handle moves ok then it is possible that the window is seized on the runners. Carefully pushing around the edges will probably move it enough for you to lubricate said runners. Have a look at a window that does open to see what I mean.

 

Or one of teh bolts is still fouling in the H-gates. Just trying to resolve a couple where I need to close the handle about 10-15 degrees aftrer opening it to let the window open fully.

 

The lock, if you mean the bit that the key goes in I assume locks and unlocks?
You have not said about the handle as if that is not fully opening (compared to a fully working one) then it will not be fully releasing the locking mechanism in the window. You need to open a functional window and explore, measure and compare the handle movement, then the mechanism on the side of the window to see what could be sticking on the faulty one. It may just need a slight push in the area where the bolts are on the side of the window and then slight adjustment.

 

As above, try reclosing the handle by 10-15 degrees.


Or using a wooden wedge, so you do not damage the UPVC, insert at teh bottom and lift the window a little.


On a working window, get a picture of teh locking mechanism in teh frame.

 

The bottom horizontal member of a top hung UPVC window can droop in the middle, especially if the casement is wide, without metal inserts; or the glass is supported in the wrong place nearer the middle instead of towards the outside.
As above, try levering the centre bottom member up slowly- the rubbers will slide on the glass & hold it in place by friction for a while.

 

have you tried to unscrew the handle and check if pin reaches the locking mechanism? or is warned out

 

SO, have you bothered to try my suggestions? Or provide the picture I suggested?

 

sprocket gone on the mechanism, if you will youtube how to open pvc window broken lock- you will find a guide - you need to have piece of steel plate and bend it in z shape, slid from the outside into the jam and slide the locking pins to open