Failed locking system on uPVC front door. We attended an address in the early hours of the morning to a failed locking system which had failed in the locked position with the door closed unfortunately… Once we’d opened the door (quietly so the neighbours didn’t get woken up!) we replaced the failed locking system part (the gearbox that does all the work). It was a WinkHaus lock (German made). These gearboxes get riveted to the full length locking system making it more difficult to replace. We removed the broken part and re-riveted a new one back in it’s place and put it back in to the door where it works perfectly.