Summary: Locks rarely fail without warning. A sticking key, a bolt that won’t fully throw, visible rust, a knob lock standing in for a deadbolt, or not knowing who holds a key are all signs it’s time to repair, rekey, or replace.
Locks almost never fail all at once. They give you weeks or months of small warnings first, and most people work around them without noticing: jiggling the key, lifting the door slightly, pulling it toward them before it will lock.
Those workarounds are the warning. Here are five signs worth paying attention to, and what each one usually means.
1. The key sticks, catches or needs jiggling
If you have developed a particular way of turning your key, that is not a quirk, it is a fault you have got used to.
Sometimes the cylinder is worn inside. Just as often the key itself is the problem: a copy of a copy of a copy, each one slightly less accurate than the last. Try your original key if you still have it. If that one works smoothly, you need a new key, not a new lock.
Do not keep forcing it. A key that has to be forced is a key that eventually snaps off in the cylinder, and that turns a small job into an urgent one.
2. The bolt will not throw fully
If you have to lift, push or lean on the door to get the deadbolt across, the lock is probably fine and the door has moved. Timber swells and shrinks with the seasons, hinges loosen, frames settle. It shows up most on older houses, which is why it is such a regular call on the long-settled streets in Kirkwood.
This one matters more than it sounds. A bolt that only goes halfway is doing a fraction of the job it was designed for, and a partially thrown bolt gives way under force far more easily than a fully seated one. It is usually a cheap fix: adjusting the strike plate or the hinges rather than replacing anything.
3. Visible wear, rust or a loose cylinder
A cylinder that rattles or turns slightly in its housing has lost its fixing, and that is worth attention quickly. Surface rust on an exterior lock usually means moisture is getting in, and what you can see on the outside is rarely the worst of it.
Locks on doors that get full weather exposure, especially west-facing ones, age noticeably faster than the rest of the house — something we see often on the newer Chesterfield Valley subdivisions. It is normal, but it means those doors are worth checking first.
4. It is a knob lock doing a deadbolt’s job
Plenty of homes still have an exterior door secured by nothing but a handle-set latch. A spring latch is designed to keep a door closed, not to keep somebody out, and it can be defeated in seconds without any tools worth naming.
This is not a fault developing. It is a lock that was never enough for the job. If any door to the outside of your home has no separate deadbolt, that is the first thing worth fixing, ahead of anything on this list.
5. You do not know who has a key
Not a mechanical fault, but the most common reason a lock stops doing its job. A perfectly good lock is worth nothing if three former tenants, an ex-partner and a builder from 2019 all still have working keys.
In this case you usually do not need new locks at all. Rekeying changes what the existing lock answers to, and every old key stops working the same day.
So repair, rekey or replace?
- Repair when the door or the alignment is the problem, which is more often than people expect.
- Rekey when the hardware is sound and the issue is who holds a key.
- Replace when the lock is worn out, damaged, or was never up to the job in the first place.
A locksmith who looks at a sticking door and immediately quotes for new hardware without checking the alignment is not doing you a favour. Ask what is actually wrong before agreeing to anything.
Recognise any of these? Call Locks R Us Locksmith on (636) 628-7803. We are out every day from 8 AM to 10 PM across West St. Louis County, and we would rather adjust a strike plate than sell you a lock you do not need. See our home lock replacement service.
