A door knob lock is expected to work flawlessly every single time it is used. For it to get stuck or simply not fasten can cause a serious security risk, depending on where the door is located. There are a number of reasons why a door knob lock can fail and get stuck.
The most common is that the oil inside the door knob lock is old and has seized, causing the lock to catch. Another common cause is that the screws on the door knob are loose. This can cause a slight void inside the door knob lock, which can also cause it to catch and get stuck. These are all problems you can repair yourself.
Step 1 - Simple Before Complicated
Sometimes the simplest solution is the best solution. Before going through the trouble of removing the entire door knob simply attempt to jiggle the door knob. Use a little force and, with any luck, the door knob lock will dislodge itself. If the latch does pop free then the problem is most likely that the door knob is loose. When you wiggle the door knob pay attention to the metal plate surrounding it. If it moves up and down that can also confirm the door knob is loose.
Use the Philips head screwdriver and begin tightening the screws on the door knob. You will find some on the knob itself on older doors. Check the circular plate and tighten the screws located there. Open the door and look at the latch plate to make sure it is centered and tighten the screws.
Step 2 - Remove the Door Knob
In order to fix a stuck door knob lock that is not a problem of the latch catching you will need to remove the door knob. On older doors you will need to remove the screws in the door knob near the plate. They are small and easy to miss. Once the screws are removed you can take off the door knob by pulling it straight off the post. You can grip the other door knob and pull to remove the entire assembly.
On newer doors you need to remove the screws from the face plate or the circular plate around the door knob. Use the flat head screwdriver to gently pry the plate from the door. You can now remove the door knob assembly.
Step 3 - Stuck Door Knob Lock
Now that the door knob assembly is removed you can take a good look at the internal components. Push on the latch to move the internal components. You will see how the door knob lock works and can then use the rag to wipe down the internal components. Use a pen to test the turning mechanism. Add lubrication and use this method to distribute it. Replace the door knob.
Replacing knobs and calling locksmiths can be costly. Now you have the knowhow to repair your stuck door knob lock this time, and any other time it may happen.