If the shoot bolts (bottom and top) can't extend all the way out, or if the latch or deadbolt can't extend fully then the lock cylinder (or thumbturn) won't be able to turn all the way. If you have enough clearance between the door and the floor, you can extend the bolts while the door is open and check to see if it turns. If it won't, there's a problem with your mechanism and it will need to be repaired or repleced. If it will turn when open but not when closed, the problem is likely that there is either dirt accumulated in the bottom hole or the door has settled enough to cause too much misallignment between the bolts and the holes. Try this...Extend the bolts with the door open. Coat the extended bolts with lipstick. Retract the bolts completely and shut the door completely. Then extend the bolts a few times, then open again. Look at the holes. If you see lipstick marks off-center of the hole, then you have misallignement. You may be able to correct the problem by shimming behind the bottom hinge and tightening the screws on top hinge (or installing longer ones). Otherwise, you can take a dremmel tool and enlarge the hole to make it large enough to accept the bolt. I hope this helps.
Lock Doc, March 2010
