A sliding door that will not lock usually has a worn mortise lock, a broken handle, or a panel that dropped so the hook misses the keeper. We replace the lock, the handle set and the keeper, keyed or non-keyed, and line them up with the door at the right height.
What you get
- Mortise lock replaced and matched to your handle set and door thickness
- Keeper replaced or repositioned so the hook catches every time
- Keyed and non-keyed handle sets in common finishes, matched to your door
- Secondary locks: foot locks, pin locks and security bars for rentals and ground floors
How a sliding door lock works, and how it fails
The handle set on the sliding panel carries a mortise lock: a small case set into the edge of the stile. Turn the thumb latch and a hook, or on some doors a latch, swings out and catches a keeper screwed to the jamb.
Three things go wrong. The mortise lock wears out: the hook will not throw, or it throws but will not stay. The handle breaks: the thumb latch snaps, the handle comes off in your hand, or the screws strip. Or the lock is fine but the door has dropped on worn rollers, and the hook simply misses the keeper.
The symptom pages cover the first signs: will not lock or latch and broken or loose handle.
Mortise lock and keeper replacement
We carry mortise locks in the common case sizes and hook styles, so most doors get a direct replacement in the same mortise. We match the lock to the handle set so the thumb latch and the hook move together, then test the throw from both sides.
The keeper gets the same attention. A keeper that has pulled loose, bent or worn a notch will not hold a good lock. We replace it or move it to meet the hook squarely, with the door at its correct height.
If the door has dropped, we fix that first. A keeper raised to meet a sagging door is a patch that fails as the rollers keep wearing. The roller page explains why.
Need a new lock or handle this week?
Call or text with your address, how many doors and what the door is doing. You get a firm price before we come out.
Handle sets: keyed and non-keyed
A non-keyed handle set locks from inside only, with a thumb latch. That is what most patio doors have, and it is fine for a door that opens onto a fenced yard.
A keyed handle set adds a cylinder on the outside, so you can lock and unlock the door from the patio. It makes sense for a balcony you use as an entrance, a rental where guests come and go through the patio, or a side-yard door. Where the cylinder allows, we can key it to match your existing house key.
Handle sets are not universal. We match the hole spacing, the stile thickness and the mortise lock type before the visit, usually from a photo of the handle and the edge of the door. We carry sets for Milgard, JELD-WEN, Andersen and the old aluminum doors that still have their original hardware.
Secondary locks for ground floors and rentals
A mortise hook is the main lock, but a sliding panel can also be pried or lifted. We add a second layer where it matters:
- Foot locks: a bolt at the bottom of the sliding panel that drops into the track, worked with your foot. Good for a door you lock and unlock all day.
- Pin locks: a steel pin through the sliding panel into the fixed panel frame, often with a second hole so the door can stay open a few inches for air.
- Security bars: an adjustable bar in the track or across the panel that stops the door sliding at all.
- Anti-lift blocks in the head channel so the panel cannot be lifted out from outside.
Ground-floor units in North Park and Chula Vista and balcony doors on vacation rentals get asked for these most. More in our guide to sliding door lock security.
Is it the lock, the handle or the rollers?
Before we quote a lock, we rule out the door height.
- Close the door and look at where the hook meets the keeper. If the hook is below the keeper, the door has dropped: that is a roller or adjustment job, and the lock may be fine.
- If the hook lines up but will not throw, or throws and springs back, the mortise lock is worn.
- If the thumb latch is loose, snapped or spinning, the handle set is the problem, and the mortise lock usually comes with it.
- If the keeper is loose or chewed, replace it; a new lock on a bad keeper still will not hold.
Often it is two of these at once, which is why we bring rollers, locks and keepers to every lock call.
Lock work across San Diego County
Roller, track and adjustment work on the same visit is minor repair, and we keep the two clearly separated on the invoice.
We see the same patterns by neighborhood. Original handle sets on 1970s aluminum doors in Santee and El Cajon are often obsolete, so we fit a modern replacement handle that covers the old holes where we can. On vinyl doors from the 1990s on, the handle is usually fine and the mortise lock is what fails. Coastal doors get corroded cylinders and keepers, and we use stainless or coated hardware there.
For landlords, a keyed patio handle or a foot lock is a cheap way to make a ground-floor unit rentable again. See our page for landlords and property managers.
Lock and Handle Replacement: common questions
Why will my sliding glass door not lock?
Most often the door has dropped on worn rollers and the lock hook passes under the keeper. Close the door and look at the hook: if it sits below the keeper, the fix is rollers or an adjustment, not a lock. If the hook lines up but will not throw or hold, the mortise lock is worn and gets replaced.
Can you replace just the handle on a sliding door?
Yes, if the mortise lock inside the door is still good. The handle set is matched by screw-hole spacing, door thickness and lock type. On most doors the handle and mortise lock are replaced together because they wear together and a matched set is the surest fix. We bring both to the visit.
Can I get a sliding door lock with a key on the outside?
Yes. A keyed handle set has a cylinder on the exterior so you can lock and unlock from the patio or balcony. It is popular for rentals, balconies used as entrances and side-yard doors. Where the cylinder allows, we can key it to match your existing house key.
Are you licensed to work on sliding door locks?
Roller, track and adjustment work on the same visit is minor repair under $1,000 in labor and materials, which does not require a California contractor license (Business and Professions Code section 7048). Ask for the license number at the door.
Which secondary lock should I add to a sliding glass door?
For a door you use every day, a foot lock is the easiest: a bolt at the bottom of the sliding panel that drops into the track with your foot. For a door you rarely open, a pin lock or a security bar stops it sliding at all. An anti-lift block in the head channel is worth adding on any ground-floor door.
Do you replace locks on old aluminum sliding doors?
Yes. The 1960s to 1980s aluminum doors across San Diego often have handle sets that are no longer made. We fit replacement handles and mortise locks that cover the original holes and match the stile thickness, or in some cases a surface-mounted lock, so the door locks again without a new panel.
More answers on the FAQ page. Not sure what your door has? Send us a photo and we will tell you.
Where we do this
We cover all of San Diego County, usually within the week. Some of the places we work:
Related guides
- Sliding Glass Door Locks and Security in San Diego: What Works – Why a dropped door will not lock, mortise lock and keeper replacement, keyed vs non-keyed handles, secondary locks that work, and what renters can do.
- Signs Your Sliding Door Needs New Rollers (And Two-Minute Checks) – Symptoms of worn sliding door rollers in order of certainty, the two-minute checks you can do safely, and how to tell when the track is the real problem.
- Repair or Replace Your Sliding Glass Door? An Honest Decision Guide – When a $250 to $400 repair brings a 40-year-old aluminum slider back, when the frame, glass or track means replacement, and typical costs for both.
Ready to get the door gliding again?
Call or text for a straight answer and a price before we come out. Mon to Sat 7am to 6pm.