Why Won’t My Deadbolt Turn? The One-Minute Test
A deadbolt that won’t turn is nearly always one of three things: grit and corrosion inside the cylinder, a bolt binding against a strike that has moved, or a worn key that no longer matches the pins. The lock itself is rarely the problem. Forcing it is how a stiff lock becomes a snapped key.
There is a moment everyone recognises. Key goes in fine. Turns halfway. Stops. You lean on it a bit harder, and somewhere in the back of your mind you already know that leaning on it harder is not the answer.
It usually isn’t. Here is how to work out which of the three you’ve got, in about a minute, before you do any damage.
First: does it turn with the door open?
Open the door, then throw the deadbolt into fresh air. This one test splits the problem in half.
| Test result | What it means | Where the fault is |
|---|---|---|
| Turns fine with the door open | The lock is healthy | The door or frame — the bolt is catching the strike |
| Still stiff with the door open | The lock is not healthy | Inside the cylinder |
Most people never do this test and end up replacing a perfectly good deadbolt because the frame moved half a centimetre.
If it turns freely with the door open: the strike has moved
Doors move. In Kenner they move more than most, because the ground under the house is soft alluvial soil and the humidity swings hard between February and August. A frame that lined up when the house was built does not necessarily line up now.
You will usually see the evidence: a shiny scrape on the strike plate where the bolt has been rubbing, or paint worn off one edge of the hole. Sometimes you can lift the door slightly by the handle and the bolt suddenly goes in. That is a confirmed diagnosis.
The fix is to move or re-cut the strike, not to buy a lock. It is about half an hour of work.
If it is stiff with the door open: inside the cylinder
Now it is the lock. Two likely causes:
- Corrosion and grit. Salt in the air off the lake, dust, and old graphite from years of well-meaning maintenance. The pins stop moving cleanly.
- A worn key. Keys are softer than the pins they push. A key that has been in a pocket for eight years is measurably shorter in places than it was. A copy of a copy is worse. Try your spare — if the spare works and the daily key doesn’t, you have your answer and it costs the price of a new key.
What not to do
- Do not force it. A key snaps when it is twisted against a bolt that cannot move. That turns a thirty-minute job into an extraction.
- Do not use WD-40. It is a solvent, not a lubricant. It strips what was there, works for a fortnight, then leaves the cylinder drier and grittier than before. Dry graphite or a PTFE-based lock lubricant is what you want.
- Do not hammer the key in. If it will not seat, something is in the keyway or the pins are seized.
The Kenner-specific version of this problem
Two local causes come up over and over.
Salt air. Anywhere north of Vintage Drive, and especially around Laketown and the lakefront, the air carries enough salt to corrode cylinder internals from the inside. A lock can look perfect and be seized solid. Cheap plated finishes go first.
Ground movement. Kenner sits on drained marsh. Houses settle, frames rack slightly out of square, and strikes drift. This is why so many locks here fail at the door rather than at the lock — and why replacing the deadbolt fixes nothing.
If the house has been through a flood at any point, add silt to the list. Silt in a cylinder is sometimes recoverable and often not.
Can you fix it yourself?
The strike alignment job, yes, if you are comfortable with a chisel and prepared to take your time. Loosen the strike plate, work out which way the bolt is catching, either file the hole or move the plate, then check the screws go into the stud rather than just the jamb while you have it off.
The cylinder cleaning job, sometimes. Blow it out, use a proper lock lubricant, work the key gently. If it comes back within a month, the cylinder is worn and cleaning is only buying time.
When it is genuinely the lock
There is one case where the answer really is new hardware: the handle or bolt wobbles, the finish is pitted, and the whole thing feels loose in the door. That is worn Grade 3 hardware at the end of its life. Cleaning it is money down the drain. There is more on what the grades mean in lock grades explained.
If you would rather not guess
Tell us which way the test went — stiff with the door open, or fine with the door open — and we can usually tell you what you are looking at before anyone comes out. Sometimes the answer is a strike screw and a can of the right lubricant, and we will say so. Ranges are on the prices page, and if it turns out to be new hardware or a rekey, those are there too.