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How to Fix a Patio Door Lock

This article is a collaborative effort, crafted and edited by a team of dedicated professionals.

Contributors: Muhammad Baballe Ahmad, Mehmet Cavas, Sudhir Chitnis, and Zhen-ya Liu.

✓ Verified & Tested Information

If your patio door lock is broken, you may be wondering how to fix it. Here are some tips on how to fix a patio door lock.

Identifying the Problem

If your patio door lock is not working properly, it is important to first identify the problem. Common issues with patio door locks can range from a broken latch or locking mechanism to a stripped lock cylinder or an issue with the door itself. By correctly diagnosing the issue, you can determine the best solution for how to repair or replace the patio door lock. Let’s take a look at how to identify the problem with your patio door lock.

Determine the type of lock

If your patio door lock is not working properly, the first step to finding a solution is to determine what type of lock you have. Patio doors typically have either a key-in-the-knob (KIK) lock, cylinder dead bolt, mortise lockset and/or handleset.

Key-in-the knob (KIK) locks are the most common type of patio door locks. They use a key on the outside and a turn knob on the inside for locking and unlocking. Some modern versions may even include an emergency release lever in case you become locked out or lose your key.

Cylinder dead bolts are also often found on patio doors. These can be confused with KIK locks as they sometimes look very similar outside of the door, but they operate differently. Cylinder deadbolts require a heavy duty key and must be manually locked and unlocked by turning the twist mechanism inwards or outwards using the key provided.

Mortise locksets feature an extra wide or ‘mortise’ frame which houses a hidden locking unit inside it giving an extra sense of security to your patio door. Mortise locksets are usually found in older styles of patio doors although some more contemporary designs do feature them too due to their superior performance over other types of locks.

Finally, handlesets are one of the newest introductions when it comes to securing your patio door from intruders; typically consisting of an exterior handle and an interior turn piece which operates similarly to that found on KIK or cylinder deadbolts but with much higher levels of protection from unwanted entry attempts than those two solutions can provide individually.

Inspect the lock for damage

In order to fix a patio door lock, it is important to identify and assess any damage to the lock itself. For example, check for visible signs of wear or damage such as broken or missing parts, as well as loose screws. It can also be helpful to inspect the measurements of the existing lock in order to purchase an identical one. Additionally, be sure to check around the entire frame and edge of the door for signs of tampering or break-in attempts.

Removing the Lock

When dealing with a patio door lock, the first step is to remove the lock from the door itself. Depending on the type of lock, this may require removing any screws that hold it in place or just unlocking it and sliding it off the door. Before removing the lock, make sure the door is securely closed. After the lock is removed, it can be examined and repaired if necessary.

Unscrew the screws holding the lock in place

The first step in fixing a patio door lock is to ensure that the door is completely closed. It also helps to stand on the inside of the doorway as you work for safety reasons. Next, you need to remove any screws that are holding the lock in place. This may involve removing screws from both sides of the door, depending on which type of lock was installed. Once you’ve unscrewed all applicable screws and removed any mounting hardware, you should be able to slide out the existing patio door lock without much effort.

Carefully remove the lock

Removing your patio door lock should be approached with care, as it holds the two sides of the door together and ensures its proper functioning. Pay particular attention to the manufacturer’s instructions from here on out.

Begin by removing any screws that hold in your lock; these generally appear on the outside side of your patio door. Once all screws are removed, you can gently slide the lock free from its frame. This can sometimes require a bit of significant effort since it takes a fair bit of pressure to push/pull both ends away simultaneously. Make sure to lift any other parts of your lock body that may still be connected for further disassembly.

When you’ve finished freeing the lock from its frame, set aside all pieces so that they are not misplaced or lost during subsequent steps in restoring your patio door’s functionality.

Replacing the Lock

Replacing the lock on your patio door can be a simple task if you follow the right steps. Before beginning, you should make sure you have the right type of lock and any necessary tools on-hand. It is also important to keep in mind that it may be necessary to drill out the old lock if necessary. This section will explain the steps you need to take in order to replace the lock on your patio door.

Measure the hole to ensure the new lock fits

When attempting to replace the lock on a patio door, it is important to measure the hole in the frame where the deadbolt will be installed before making a purchase. By doing this, one can ensure that they buy the correct size of lock and that it will fit correctly when installed. Measuring correctly can save time and energy that would have gone into returning or exchanging an ill-fitting lock.

It is advised to use a flexible measuring tape which can access difficult areas and measure with greater accuracy than a rigid ruler. Start by measuring both the height and width of the hole separately, making sure that all measurements are as exact as possible. Taking notes while measuring may also be beneficial if multiple locks need to be measured for comparison or potential replacement.

In addition to taking measurements of the hole in which the deadbolt will go, one should also measure other areas such as door thickness and handle placement since these are integral for finding a compatible lock for installation. Therefore, having exact measurements is essential for finding a good fitting lock – delaying or bypassing this step could lead to an ill-fitting or incompatible lock being purchased, leading to extra time spent replacing or exchanging locks in order find one suitable for installation in your patio door.

Install the new lock

Before installing the new lock, check that the latch plate is fitted in the right direction and that it fits tightly against the door. Place the jamb strike plate in position and trace around it with a pencil so you know where to drill. The screws for the strike plate should not go into a hollow part of the frame.

Next, take out the new patio lock from its packaging and attach it to place prior to drilling. Only after correctly installing it should you mark where you need to drill for mounting with screws. Carefully drill and insert the screws into each of the marked holes, ensuring that all have been tightened securely.

Finally, test out your new patio door lock by attempting to slide your door open and closed various times. You may find it helpful to lubricate your hinges using a light oil, spray silicone or graphite powder – this will ensure that they move smoothly and help improve your security features in the long run!


When your patio door lock is not working properly, it can be a difficult task trying to diagnose and fix the problem. Fortunately, there are a few steps you can take to troubleshoot and hopefully solve the issue. Before attempting any repairs, it is important to understand how the lock should be working and what the possible causes of the problem could be. This article will guide you through the troubleshooting process so that you can get your patio door lock working again.

Inspect the lock for any obstructions

When troubleshooting a patio door lock, start by inspecting the lock for any obstructions that may be interfering with the closing and locking mechanism. Check for dirt buildup or debris that can prevent the latch bolt from fully engaging in the strike plate. If you still cannot open, close or lock your patio door, it is likely an internal mechanical lock malfunction and will require further disassembly to identify and address the cause.

Test the lock to ensure it is functioning properly

The first step when troubleshooting a patio lock is to make sure it is functioning properly. To begin, try unlocking and then locking the latch. If you are having difficulty, close and open the door several times in order to see if the latch grinds or does not fasten securely. If possible, test the door from both sides so that you can note any inconsistencies from both directions. Make sure to listen closely for any strange noises or grinding sounds that may indicate a problem with the mechanism of the lock.

After testing, we recommend lubricating all moving parts of your lock with graphite or specialized lubricant made for patio doors. This should help ensure smooth operation of the lock and reduce friction caused by lack of maintenance over the years. If signs of wear are present, consider replacing parts such as compressed springs or worn gears before lubricating them as they may be past saving and more likely to cause more damage during prolonged use.

If testing and lubricating your patio lock do not restore proper working order then our experienced technicians are available to assist in repairing any faulty locks quickly and efficiently

Finishing Up

Once you have successfully finished replacing your patio door lock, the most important thing is to make sure that you have properly tested it. Lock and unlock the door multiple times to make sure that it is functioning properly. You may need to make slight adjustments to the door frame in order to make sure the latch and cylinder are installed correctly. Take your time and double-check everything before you declare the job finished.

Re-screw the lock in place

Once the desired level of security has been achieved, the final step is to re-screw the patio door lock back into place. Make sure that all screws have been properly tightened to ensure a secure fit. Afterward, use sandpaper to smooth out any rough edges on the frame or door and check for any snags or damage that may need repairing. Once everything is checked and in good order, your patio door should be ready for proper operation.

Test the lock again to ensure it is working properly

Before putting everything back together, make sure to test the lock a few times to confirm that it is working properly. Ensure that when you turn the inside knob, it releases the external latch and unlocks the door. Conversely, turning the outside knob should open the lock with a satisfying click. Rewind any spring mechanisms before you finish putting your tools away and then check one more time to confirm that all moving parts are in place and in proper working order. When finished, enjoy your nicely functioning patio door with added peace of mind knowing that you have successfully fixed it yourself!

How to Fix a Patio Door LockCheckout this video:

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