Security screen door lock not working? Check these first
Updated
The short answer
A security screen door lock that stops working can be a fitting or alignment fault, with the lock itself still fine. Austral Lock's troubleshooting sheet for its Elegance XC lock says malfunctions are usually the result of incorrect installation, and its first test costs nothing: work the lock with the door open.
6 sections and 5 questions, about 8 minutes
If the lock behaves with the door open, look at the door and the strike plate. If it still fails, a fault in the cylinder or the lock itself is more likely. The sections below sort the usual faults by what you notice, with a safe check for each and the point where it becomes a repair job.
Match the symptom to the cause, starting with the door open
The fastest way to narrow down a faulty security door lock is to test it twice: once with the door open, once with it shut. Austral Lock's troubleshooting puts it plainly. If the lock works correctly with the door open, there's a fitting problem rather than a lock problem.
A lock that fails in both positions is more likely a fault in the key, the cylinder or the lock itself, which is a job for a repairer. A lock that only fails when the door is closed points back to the fitting, such as a strike plate the bolt can't get into. Use the list below as a rough guide to the likely cause, then jump to the matching section.
Key won't turn, even with the door open: more likely the cylinder or the lock body.
Key turns with the door open but not shut: the bolt can't slide fully into the strike plate.
Door swings shut but won't stay closed: the trigger bolt isn't being pressed as the door closes.
Triple lock grabs in the middle only: a top or bottom bolt may not be meeting its keeper.
Handle moves but the latch doesn't: the fault is likely between the handle and the latch inside the lock.
Key will not turn or is stiff: keep oil out of the cylinder
For a stiff key, Gainsborough, which makes Austral Lock hardware, recommends a little dry graphite and no oil in the keyway. Its care advice says don't put oil or aerosol lubricant in the cylinder. When a key goes sticky, sprinkle a small amount of graphite onto the key and slide it in.
Keep cleaning water out of the keyway too. Gainsborough says soap and water shouldn't be used on cylinders and liquid shouldn't get into one at any time. It also notes that dust or a harsh climate can affect the lubricant a lock leaves the factory with, so a lock that once turned freely can stiffen over the years.
If graphite doesn't free the key, and the key still won't turn with the door open, stop there. A fault in the cylinder or the lock body is more likely, and that's a repair job. One clue worth passing on: if the trouble started after someone tightened the screw that holds the cylinder in place, say so. Whitco warns that over tightening the cylinder screw on its Leichhardt sliding lock may jam the locking mechanism.
Door closes but will not latch: check the gap and the strike plate
When a security door shuts but won't latch, check whether the small trigger bolt is being pressed as the door closes. On Austral Lock's Elegance XC, a door that won't lock or won't stay closed indicates the auxiliary bolt isn't being tripped. Their fix is to bring the gap between the door and the strike plate down to no more than 3 mm, by packing the hinges or the strike plate.
A related fault shows up when the lock will lock with the door open but not once it's shut. Austral Lock traces that to the main bolt being blocked from sliding fully into the strike plate hole, because the hole isn't deep or wide enough.
There are two owner checks before calling anyone. Wipe the strike plate with a soapy rag, which Austral Lock lists as a quarterly job that clears built up grime and stops the door bouncing. Then look at the hinges and tighten any screw that's plainly loose. If the gap is still wide after that, packing hinges or recessing the frame is fitting work, so book it as a repair.
Triple lock only catching at one point: check where the outer bolts land
A triple lock that only grabs in the middle may have a top or bottom bolt that isn't lining up with its keeper. Those extra bolts are worked from the main lock. Whitco's 3 point lock kit, for example, comes with rods, two auxiliary locks, a keeper and screws, and Austral Lock's Elegance XC is compatible with Elegance cable and rod multipoint kits.
The owner check is a slow look. Close the door gently and watch where the top and bottom bolts land. A bolt striking the frame beside its keeper, or a keeper that has shifted, gives a repairer a useful head start. Austral Lock's annual maintenance asks for the same thing in general terms: a door that runs with the right clearances and opens and closes without anything in the way.
Leave the rods and cables alone. Adjusting them means opening up the door and the lock.
Handle spins or feels loose: tighten the screws, then stop
A loose security door handle is the one lock fault an owner can sensibly check with a screwdriver. Look for the screws holding the handle sets to the door and give any loose one a snug turn. Go gently. Whitco's fitting steps for its Leichhardt lock say to secure all the screws but not to over tighten the handle securing screws.
If the handle firms up and the latch pulls back when you press the handle, that was the whole problem. If the handle still spins, flops or moves without drawing the latch in, a fault between handle and latch inside the lock is more likely, which is a job for a repairer.
That's where an owner check ends. Austral Lock states its Elegance XC lock assembly is lubricated for life and shouldn't be taken apart by the user, and the same caution makes sense for any mortice lock sitting inside a security door. Book it in as a repair job rather than living with a handle you have to jiggle.
Repair or replace the lock: the door-open test decides
Whether a security door needs a new cylinder, a whole new lock or just an adjustment comes back to the door-open test. Austral Lock's rule is that a lock working correctly with the door open means a fitting problem, so the fix is in the hinges, gap, strike plate or keepers rather than the lock.
If the key is the trouble, the cylinder can often be swapped on its own. Whitco sells security door lock bodies with no cylinder, to take a separate Whitco Euro profile lazy cam cylinder, and its Tasman MK2 lock accepts the same type. Matching the brand matters. Whitco states the warranty on its Leichhardt lock won't apply where a fault comes from a non-genuine Whitco cylinder.
A jammed key or a lock that has stopped catching is something we fix by fitting a new cylinder or a new lock, and the same visit can cover a worn triple lock, patio bolt, hinge or closer. To protect the finish on coastal doors, Austral Lock suggests cleaning powder coated surfaces every two to three months in coastal areas, which fits a regular screen wash.
Questions we get asked
Can you replace just the lock cylinder on a security door?
Often, yes. Whitco sells many of its hinged and sliding security door locks with no cylinder, to take a separate Whitco Euro profile cylinder, so a jammed or worn cylinder can often be changed without replacing everything. Ask for a cylinder from the same maker as the lock. If the lock body itself is worn or broken, a new cylinder on its own won't fix the fault.
Why does my security door only lock when I push it?
The door may not be fully latched until you push it, and some locks refuse to lock before that point. Whitco builds its Leichhardt sliding lock so it can't be locked until it's fully latched to the striker. On Austral Lock's Elegance XC hinged door lock, a gap of more than 3 mm between door and strike plate can stop the trigger bolt being pressed, and their answer is packing out the hinges or the strike plate.
Should I put oil in a security door lock?
No. Gainsborough, which makes Austral Lock hardware, says not to use oil or aerosol lubricant in the cylinder. A pinch of graphite on the key is their answer to a sticky keyway. For the working mechanism they name silicone or Teflon based lubricants, though Austral Lock says its Elegance XC lock assembly is lubricated for life and should not be taken apart by the user.
How often should I check a security door lock in coastal Cairns?
Austral Lock's schedule is a good guide: wipe the strike plate with a soapy rag every three months, and once a year confirm the door closes cleanly and locks by both key and snib with the door shut. In coastal areas they suggest cleaning powder coated hardware every two to three months, which covers a coastal city like Cairns and pairs easily with a screen wash.
Do you repair security door locks in Cairns?
We do, at your place. Our repair work covers lock cylinders, complete locks, triple locks and patio bolts, along with hinges, closers, wheels and tracks on the same door. When you book, tell us what the lock does with the door open and with it shut. That one detail helps us work out early whether the lock or the fitting is at fault.
Where this comes from
The published sources this guide draws on, and the date each one was checked.
