#1 Deadlatch not working.
The deadlatch is designed to prevent the opening of a door by manipulating the latch with a credit card, ice pick, knife point, or other tool. In order to work, the deadlatch must be depressed when the door is closed. If it is not depressed, or falls into the strike opening, it will fail to function. The cause of this problem is normally a poor original installation. An excessive gap between the door and the jamb may also cause the deadlatch to fail. In addition to allowing the lock to be easily bypassed, any binding pressure against a deadlatch that falls into the strike may break the deadlatch or cause the latch to fail.
Careful observation of the strike while slowly closing the door will usually reveal a problem. The latch should fall into the strike, but the deadlatch should not. Two distinct clicking sounds when the door is closed may also reveal a problem. Because of the weather-stripping used to insulate homes, amisaligned deadlatch is a common problem in new as well as older homes. A properly installed door should have a gap of approximately 1/8 inch between the door and the jamb. Adjusting the strike position, or placing shims behind the strike will usually solve these problems.
#2 Deadbolt not fully extending.
If the bolt does not extend completely, it does not actually lock, and can be pushed back with an ice pick or knife point. Most deadbolts are designed to extend a full inch. If the door jamb/frame has not been bored out enough to allow the full extension, the bolt does not lock in place. If the bolt binds against the strike plate, it might also be prevented from locking in place.
Operate the deadbolt with the door open and observe how far the thumbturn is rotated to fully extend the lock. Repeat with the door closed. If the thumbturn does not rotate as far, the bolt is probably not extending completely. If you hear the thud of the bolt hitting wood rather than the click of the bolt locking in place, there is probably a problem. Any binding pressure against the bolt can also cause lock failures. If you must push, pull, or lift the door to operate the deadbolt, there is a problem. Like entry locks, deadbolt strike positioning is critical.
Repairs normally consist of adjusting the strike position and/or boring out the door frame to allow full extension of the bolt. Additionally, since the deadbolt is the primary defense against forced entry, it is important that the strike be secured to the framing around the door, not just to the trim. Many deadbolts come with ¾ inch screws to attach the strike plate. They do not offer much protection. Replace these with 3” screws that tie the strike plate to the 2×4 framing around the door.
#3 Master pins in lock.
The first two problems are found in new homes as well as older ones. The third is found primarily in newer homes, especially in single-builder communities.
Some builders use locks that are construction master-keyed. The construction master key can be used to access several homes. When the homeowner’s key is used in the lock, the construction master key will no longer operate the lock. Unfortunately, since many builders use locks that are construction master-keyed (designed for access to several homes) rather than simply construction keyed (access to a single home until the homeowner’s key is used), many locks are left with as many as four master pins inside them. Every master pin doubles the number of keys that will operate a lock. The existence of master pins reduces the security of a lock, increases the likelihood of failure, and causes unnecessary wear on the lock. A lock with master pins is also more susceptible to picking or bumping.
We believe the homeowner has a right to expect that the key they are given is the only key that will operate the locks on their home. A lock with four master pins can be operated by sixteen different keys. There is no justification for leaving master pins in a residential lock without the owner’s knowledge and consent.
Unfortunately, it is difficult to determine whether a lock has master pins without disassembling the lock. Locks with master pins may not operate as smoothly as one without. Rough operation or difficulty in inserting or removing the key may indicate the presence of master pins.
Locks should be rekeyed whenever there is a change of ownership. The possible existence of master pins in a lock makes this as true for new homes as older ones. If you live in a single-builder community, have the locks rekeyed. Your home will be more secure and your locks will last longer.