Door locks are usually reliable, but sometimes they lock out the homeowner. Freezing weather, misalignment, and a jammed latch are among the more common problems with exterior residential door locks. Try these quick fixes to coax the tumbler to move.
Metal parts use lubrication to reduce wear from the friction of everyday use. Parts that are not properly lubricated can freeze when exposed to inclement winter weather. Spray a small amount of graphite onto both sides of your door key and then insert it in the lock. If it is still jammed, then try to spray some inside the key hole. You might have to move the key from side to side until the tumbler moves. Be gentle so you don't break the key.
Graphite is a lubricant that works well in freezing weather. It's a good idea to keep a small container of graphite in the trunk of your car. It's very inexpensive and works equally well on car door locks.
Parts become misaligned more commonly on older wood doors. Wood loses it natural oils after repeated exposure to the weather. As a result, the door shrinks a little. If the shrinkage occurs around the lock, then it can jam.
This fix requires that you have a different way to get inside the house. You need to remove the faceplate and then the lock. The screws are on the inside of the door for security purposes. Remove the faceplate and lock, and either replace it or drop it off at the locksmith's shop for repair.
If you cannot get into your home through another method, call a professional locksmith. He has the training and tools to force the lock. This is more expensive than dropping it off for repair, but you won't have to fiddle with a stubborn lock.
When a lock jams on a new door, then it probably has not been hung correctly. The only real solution is to remove the door and adjust it.
Door Latch Won't Budge
If the key turns but the door latch doesn't retract, then try to move it with a thin, dull object. Try a putty knife or flat-head screwdriver if the opening is wide enough. Otherwise, use the time-honored credit card trick. Do not, however, use a good credit card, as it might damage the magnetic tape.
You have two more choices if neither of the above tricks work. Remove the door or call a locksmith. It's probably better to call a locksmith since they will need to repair the lock anyway.