A lock that turns freely while the door refuses to open is one of the more disorienting failures a door can produce, because the part you can see is working and the part you cannot see is not. The key rotates, the thumbturn rotates, the lever drops, and the door does not budge. Most people respond by turning harder, pulling harder, or both. A locksmith standing in front of that same door does something different in the first sixty seconds, and it is worth describing that minute in detail, because almost every one of those observations is something you can make yourself before anyone arrives.
Second one to ten: which lock is the one that turned
The first glance is at the door as a whole, not at the lock that was reported. Most exterior doors carry two locks, a knob or lever latch and a deadbolt above it, and a fair number of doors carry a third, whether a surface bolt, a chain, a slide bolt at the top, or a second deadbolt that a previous owner added. The question is simple: which of these did the caller turn, and which of them is still holding the door.
A surprising share of these calls end here. The thumbturn on the deadbolt was rotated, the bolt retracted correctly, and the door is still held by the knob latch, which is locked and was never unlocked. Or the reverse, the key was turned in the knob, and the deadbolt is still thrown. Or an interior door has a privacy button that was pushed. On an outswinging commercial door, a flush bolt at the top or bottom of an inactive leaf may be engaged. The pro checks every locking point on the door before deciding that any single one has failed, because a lock that turns and a door that stays shut is exactly what a second, still engaged lock looks like from the outside.
If you are at the door now, count the locks. Operate each one and watch what happens. If any of them does not move at all, that one, not the one that turns, is holding the door.
Second ten to twenty: the sound and the feel of the turn
Once it is clear that the turning lock is the only one engaged, the next observation is about the quality of the turn itself. A locksmith turns the key or thumbturn slowly and pays attention to two things: whether there is any resistance at all, and whether there is a click or a thunk at the end of the rotation.
A healthy deadbolt has a definite feel. The turn loads slightly as the cam pushes the bolt, then releases as the bolt seats, with a solid stop at each end. When the turn is completely free, spinning with no load and no stop, the connection between the cylinder and the bolt mechanism is gone. On a deadbolt that is almost always the tailpiece, the flat metal bar that runs from the back of the cylinder into the bolt housing. Tailpieces snap, shear at the cylinder, or drop out of the housing when a retaining clip fails, and once that happens the cylinder turns as if nothing is attached to it, because nothing is.
On a knob or lever, the equivalent free spin means the spindle has broken or has come loose from the latch. The knob rotates but the retractor inside the latch never moves. Lever handles add a second failure: the spring cassette that returns the lever to horizontal can break, so the lever droops, and depending on the design the lever may then rotate without engaging the hub. A lever that hangs downward at rest while the door stays shut is telling you the inside of that lockset has come apart.
A turn that loads but stops short, meaning the key rotates part way and hits a hard stop while the door stays closed, is a different case. The mechanism is connected, but something is stopping the bolt from moving. That leads to the next observation.
Second twenty to thirty: the gap between door and frame
A locksmith now looks at the edge of the door where it meets the jamb, and if the gap allows it, shines a light into the space between the latch edge and the strike. What is visible in that gap decides the whole job.
If the bolt can be seen still extended into the strike while the lock is in the unlocked position, the bolt is not retracting, and the reason is inside the lock body or in the pressure the door is putting on the bolt. If the bolt is retracted and the latch is retracted and the door still will not open, the door is bound in its frame, and the lock is innocent. If the latch bolt is retracted but the small deadlatch plunger next to it is caught on the edge of the strike opening, the plunger has dropped into the hole and is holding the door, which is a strike alignment problem rather than a lock problem, and our page about a door latch not catching strike plate explains how a door gets to that point.
Pressure on the bolt deserves its own explanation, because it is the single most common reason a connected, working deadbolt will not retract. The bolt sits in the strike opening with very little clearance. If the door has swollen, sagged, or been pushed by a warped frame so that the edge of the strike opening is bearing against the side of the bolt, the friction can be higher than the cylinder cam can overcome. The key turns part way, loads up, and stops. Pulling the door tightly closed or lifting the knob while turning the key often relieves that pressure and lets the bolt slide. If that works, the lock is fine and the door is not square, which is a hinge and strike correction rather than a lock replacement.
Second thirty to forty: the door itself
The pro now presses the door at the top corner and the bottom corner on the latch side and watches for movement. A door that flexes at the top but not the bottom, or that will not flex at all, is being held somewhere specific. A door that is stuck across its whole height, with both locks retracted, has swollen into the frame or the frame has closed in around it. In a humid coastal climate this is far from rare, especially on wood doors and on doors that have not been painted on their top and bottom edges, which is where they take on moisture.
The weather seal is checked at the same time. A compression seal that has stiffened or been painted over can hold a door with more force than people expect, and a door that was slammed against a stiff seal can be wedged into it. A threshold that has lifted, or a door sweep that has caught on a rug or a tile edge, produces the same feel from the inside. None of these are lock failures, and a locksmith who cuts into a lock without checking them has made the job worse.
The pro also glances at the hinge side for a reason that is easy to miss. A hinge pin that has walked partly out, or a hinge whose screws have pulled loose, can let the door drop on the latch side by enough to jam the bolt in the strike while the lock turns fine. Lifting the door on the knob and trying again relieves it, and the fix is at the hinge.
Second forty to fifty: the type of lock and what it fails at
By now the locksmith has identified the general category, and the last quick observation is about the specific hardware, because each type fails in its own way and the approach to opening it depends on which one it is.
A tubular deadbolt, the common residential type, fails at the tailpiece or at the bolt housing’s internal cam. A knob lockset fails at the spindle, the retractor spring, or the latch itself, whose internal parts can seize so the bolt stays out no matter how the knob turns. A mortise lock, common on older homes and on commercial storefronts, is a single large case inside the door edge with a hub, a series of levers, and both a latch and a bolt in one body. When a mortise lock turns without opening, the hub has usually cracked or the spindle has stripped its square hole, and because the case is inside the door, the repair is different from a bored lock. A storefront lock with a hook or pivot bolt fails when the bolt hangs up in the keeper on a door that has dropped, which is common on aluminum doors whose pivot has worn. A push bar or exit device that will not release is a separate specialty, and our page about a push bar door won’t latch problem describes that hardware in detail.
Knowing which type is in front of them lets the locksmith reach for the right approach rather than a general one. It also affects what not to do, which is the subject of the next section.
Second fifty to sixty: deciding how to get in without damage
The last ten seconds are a decision. If the door is bound in its frame, the answer is to relieve the binding, usually by lifting, pushing at the right corner, or working the seal loose, and no lock work is needed at all. If a second lock was still engaged, it gets unlocked normally. If the tailpiece or spindle has broken, the bolt is still fully extended with nothing connected to it, and the question becomes how to retract a bolt that has no lever attached.
On most residential deadbolts, removing the interior thumbturn assembly exposes the back of the bolt housing and often lets the bolt be pushed back directly with a tool. On a knob lockset, removing the interior knob and rose gives access to the spindle hole in the latch, where a screwdriver can usually rotate the retractor. On a mortise lock, the interior trim comes off and the hub can be turned with a square drive or a spindle stub. In a small number of cases where the door is locked from the outside and there is no access to the inside, the cylinder itself is picked or bypassed to expose the tailpiece, or the bolt is manipulated through the gap. Drilling is the last option and a competent locksmith reaches it rarely, because a drilled lock is a destroyed lock and the door was almost certainly openable another way.
What you can safely do yourself before anyone arrives
Almost everything in the first sixty seconds is observation, and it costs nothing. Count the locks and operate each. Turn the lock slowly and feel for load and for a stop. Look into the gap with a flashlight. Press each corner of the door. Lift the door by the knob while turning the key. Pull the door tightly closed and turn again. Try the other side of the door if you can reach it, since a deadbolt that will not retract from the outside key will sometimes retract from the inside thumbturn, because the tailpiece is broken on only one side of the cylinder.
If the door is an outswinging door and you are on the inside, and the lock has clearly failed rather than the door being bound, removing the interior trim is within reach for many homeowners and often exposes enough of the mechanism to retract the bolt. Take a photo before removing anything so it goes back the same way.
What not to do, and why it costs more later
Do not turn the key harder. If the tailpiece is broken, more force does nothing. If the bolt is bound, more force snaps the key off in the cylinder, and now the door is still shut and the keyway is blocked. Our page on a key broke off in lock situation explains how that changes the job. Do not pry the door at the latch edge with a screwdriver or a bar. It splinters the jamb, bends the strike, and on a steel door creases the skin, none of which makes the bolt move. Do not remove the hinge pins on an exterior door from outside in an attempt to swing it from the hinge side, since the door is still held by the bolt and will not come free, and the pins may not go back. Do not kick a door that has a bolt thrown, because the bolt does not break, the jamb does. Do not spray lubricant into a lock that is free-spinning; it has nothing to lubricate.
When this is a locksmith job and when it is not
Broken tailpieces, stripped spindles, seized latches, cracked mortise hubs, failed lever springs, and bolts bound by misaligned strikes are all locksmith work, and every one of them can usually be resolved in a single visit with the door opened without damage. A door that is bound in its frame because the frame has moved, the slab has settled, or the door has swollen past what planing can fix is a carpentry job once the door is open, though the locksmith will usually get it open. A storefront aluminum door whose pivot has failed and dropped the door onto its bolt may need a glazier or a door contractor for the pivot after the lock is dealt with. An electric strike or maglock that will not release on a commercial door is a locksmith job if the hardware failed and an electrician’s job if the power to it did.
What the full visit looks like after the first minute
Once the door is open, the failed part is identified for certain. A broken tailpiece means a replacement tailpiece or, more often, a new deadbolt, because tailpieces are specific to the cylinder and the bolt housing and mixing brands rarely works. A stripped spindle means a new lockset. A seized latch means a new latch of the correct backset. A cracked mortise hub can sometimes be replaced within the case, and on quality mortise hardware that is worth doing, but on lighter residential mortise locks the whole case is usually swapped.
If the cause was binding rather than a broken part, the visit shifts to the door. Long screws in the top hinge, the strike relocated, the deadbolt strike opened slightly to give the bolt clearance, and the weather seal checked. The lock that was blamed at the start turns out to be fine, and the fix is on the door it sits in.
Keeping it from happening again
Deadbolts and latches last longest on doors that are square. Once a year, lift the door by the knob and check for play at the hinges, and drive long screws into the top hinge before the sag begins. Throw the deadbolt with the door open every so often and watch that it extends and retracts freely, because a bolt that is stiff with the door open is about to be impossible with the door closed. Turn keys with a light hand and replace a key that has started to feel rough. Paint or seal the top and bottom edges of exterior doors so they take on less moisture in the wet season. Do not let a lever that droops or a thumbturn that feels loose go for months, because those are the early signs of the spring and tailpiece failures that end with a door that will not open.
When the first minute of observation points to a broken tailpiece, a spindle that has let go, or a bolt that will not clear its strike, that is work Pro Locksmith performs on residential and commercial doors across Broward County, including through our 24-Hour Emergency service. Call (954) 406-8266 and describe what you saw in the gap and how the turn felt, and the technician will arrive knowing which of these it is.