How to Fix a Door That Will Not Lock

A door that will not lock can potentially be not only a frustration, but a very real danger. While an interior door that refuses to lock generally remains merely an unpleasant situation, leaving an entry door unlocked may eventually result in an unwanted entrance from a criminal. How best to fix a door that won't lock depends in great part upon the malfunction that stands in the way of proper closure.

Difficulty: Moderate

Instructions

Things You'll Need:

• WD-40
• Lighter

1. Lubricate the keyhole with WD-40 or some other silicone spray if the problem is that the key will not enter into the lock's cylinder. The cylinder could be obstructed by dirt, ice or some other particle. The dirt can be cleared away with the spray, but if the problem is ice in the cylinder you may have to hold the key over a flame until it gets hot enough to melt the ice.

2. Remove the rose (the rounded object that connects the cylinder to the knob), if the problem is that the key will enter the lock, but not turn. Rotate the lock's cylinder until it interlocks. The problem may be that the tumblers inside the lock somehow got damaged. If this is the case, you may have to replace the cylinder.

3. Lubricate the bolt with WD-40 if the problem is that the key turns, but the bolt itself won't move. The bolt probably got jammed with dirt or possibly even paint. If the bolt does not line up precisely with the strike plate, then you'll have to adjust the strike plate to get the door to lock again.

4. Adjust the door hinges if sagging is the reason behind the bolt of the lock failing to reach the strike plate. Shimming is required if the strike plate has recess too far into the doorway for the bolt to reach it.

5. Check to make sure a key or other object has not gotten lodged into the lock hole. If this is the case then you should remove the cylinder and force the object out. If shaking the cylinder fails to do the job, try inserting a very thin piece of wire into the keyway to dislodge it.