Defective or Non-Functioning Locks FAQs

Q: I bought some Master Lock door hardware a few years ago, and it's not functioning properly. How do I get it replaced?


In December 1997, Master Lock sold off an older division which made door hardware products. However, we are still honoring the warranty. Please call 1-800-308-9244 for information regarding warranty.

Note: We do not have any replacement parts available for door hardware products purchased prior to 1997.

If you purchased Master Lock door hardware products after March 2, 2006, you can find more information regarding these products at

Q: If my lock is broken, should I repair or replace it?


In most circumstances, a broken lock cannot be repaired. For personal safety and security, you should always replace your broken lock with a new one.

Q: Why can I open my locked front door with just a credit card in 3 seconds?


This problem is caused by a misaligned strike plate. Keyed entry locks use what is referred to as a dead–locking "dog". If you were to look at the end of the latch, you will see two spring loaded bolts. The first is large and tapered and is intended to spring through the strike plate. The smaller flat bolt is the "dog".

For proper operation, the strike plate needs to be aligned such that the dog does not pass through the strike plate opening. if it does, the latch can be worked back with a credit card or screw driver. If the dog stops on the strike plate, the latch cannot be worked back. It is then "deadlocked" into position. Realigning the strike plate should alleviate the problem.

Q: After installing my deadbolt, why does it not work correctly?


It is critical that the deadbolt tailpiece be horizontal when inserted into the retracted bolt during installation. In addition, the dimple in the thumbturn shaft must be pointed downward for proper Nightwatch operation.