I am having issues with an exterior door from my walkout basement. We closed on buying the house March 20 and it worked fine until a few days ago. I tried to open it from the inside and it wouldn't open. At first I attributed it to humidity and a little binding because we just got some rain and heat, but after further inspection, the top latch of the 3 point latch system won't retract with the turn of the handle. After some careful and creative work with a few screwdrivers and a flashlight, I forced that top latch in and opened the door. Its very odd because the locking mechanism works fine, pushing all three latches further out, and the center and lower respond fine to turning the handle, and retract to open the door as required. Just that stupid top one will either do nothing when I turn the handle, or move 1 mm for a moment and still refuse to retract. I can push it in with my hand or a screwdriver but I can't get it to respond to the handle. I took the handle off, and tried to take the top latch out but clearly they are all connected by a system of connecting rods inside the door and I can't get them out. It seems as though the 3 point locking system is integrated to the door unless I am missing something. I don't know if its safer to have it permanently locked or permanently unlocked, but for now I put a few pieces of tape across the top latch trim piece to keep it inside the door so for now I have a functional door that won't lock.
How do I solve this problem? I'd like to get away without replacing the whole door if at all possible.