Unlocking The Secrets: Troubleshooting A Faulty Door Lock

A broken door lock can result in a lack of privacy and even the risk of being locked in or out of a room. It is therefore important to fix any issues as soon as they are noticed. This could be the lock sticking, the lock loosening, or the key not turning in the lock.

There are several DIY solutions to repairing a door lock that doesn't work properly.

Check if the door latches are engaging properly

If your door lock doesn't latch properly, it usually means the door latch and the strike plate on the door jamb are out of alignment. Here are some steps you can take to check and fix this issue:

Step 1: Tighten the Door Hinge Screws

Start by tightening the door hinge screws. This simple adjustment might be enough to realign the door latch and strike plate.

Step 2: Observe the Latch Bolt and Strike Plate

Close the door slowly and observe how the latch bolt meets the strike plate. Check if the latch bolt is positioned above, below, or to the side of the strike plate. There may be scars or wear marks on the strike plate that indicate the "route of travel" of the latch bolt.

Step 3: Mark the Latch Bolt Positions

Stand on the hinge side of the door and close it until the latch bolt just touches the strike plate. Use a pencil to mark the positions of the top and bottom of the latch bolt on the strike plate.

Step 4: Check the Alignment

Open the door and examine the alignment of your marks with the strike plate opening. If either mark falls outside the top or bottom of the opening, you'll need to make adjustments to the strike plate or the door itself.

Step 5: Adjust the Strike Plate

If the latch bolt and strike plate are misaligned, you have a few options:

• Move the strike plate to a position that allows the latch to engage properly. This may involve chiselling out a small amount of wood above or below the strike plate to create more space.
• Enlarge the strike plate opening by filing the inside edges. This option is often preferable, as it doesn't require filling or touch-up painting.
• Replace the strike plate with an adjustable door strike, which can be purchased from hardware stores or online.

Step 6: Check for Obstruction

If the route of travel aligns with the strike plate opening, check for any obstruction. Ensure that the wood from the jamb has been completely cleared away from the strike opening. Use a chisel or utility knife to remove any remaining wood carefully.

Step 7: Adjust the Strike Plate Distance

If there is no obstruction, the strike plate may be set too close to the doorstop molding, preventing the door from closing far enough for the latch to engage. You can relocate the strike plate by moving it away from the doorstop molding. Alternatively, you can break off the tang (the metal piece that bends into the hole under the strike plate) using pliers or a vise grip. Filing the stump smooth will add extra space for the latch to engage.

Step 8: Test the Latch

After making the necessary adjustments, test the latch by closing the door slowly and observing if the latch bolt now aligns and engages properly with the strike plate.

Clean the lock with graphite or a dry lubricant

If your door lock is not working properly, it may be because it is dirty or needs to be lubricated. You can use graphite or a dry lubricant to clean your lock. Here is a step-by-step guide:

Using Graphite to Clean Your Lock:

Graphite is an excellent lubricant and a great way to fix a lock that is becoming difficult to unlock. You can buy powdered graphite lubricant in small bottles with a nozzle, making it easy to squirt a small amount directly into the lock. Here is what you need to do:

• Squirting a small amount of graphite powder into the lock. Less is more—use it sparingly as the powder is very fine and can go everywhere.
• Wear disposable gloves to protect your hands.
• Try squirting graphite powder onto the key itself first.
• If you are using it outdoors, do it on a calm day to avoid the powder blowing away.
• Insert the key into the lock and turn it a few times to distribute the graphite.
• Repeat the process if needed until the lock mechanism feels silky smooth.

Alternatively, if you do not have access to graphite powder, you can use a pencil. Here is what you need to do:

• Remove the "lead" from a pencil. If it is a wooden pencil, use a sharp knife to whittle away the wood surrounding the graphite.
• Stick the chunk of graphite into the keyhole. You may need to twist it to get it in.
• Insert the key into the lock and slide it in and out a few times. This will grind the graphite into a fine powder.
• Try turning the key. If it meets resistance, continue jiggling the key until the graphite is fully ground and the lock mechanism is lubricated.
• Repeat the process if needed.

Using a Dry Lubricant to Clean Your Lock:

If you do not have access to graphite, you can use a dry lubricant spray, such as GT85 Cleaner or 3-IN-ONE Lock Dry Lube. These products are designed to clean and lubricate door locks and are widely available. Here is what you need to do:

• Attach the small plastic straw that comes with the product to the nozzle.
• Squirting the lubricant directly into the lock.
• Wear gloves to protect your hands from any excess liquid that may drip out.
• Have an old rag or towel handy to catch any drips and protect your surfaces.
• If your lock is very sticky, you may need to apply the lubricant multiple times.
• If necessary, remove the lock from the door and turn it upside down to allow excess liquid and dirt to drip out.

Fix a broken key inside the lock

If a key breaks inside a lock, it can be a stressful situation. Here are some methods to help you fix this problem:

• Do not use the key again: If you try reinserting the key, you will push the broken part further into the lock, making it harder to remove.
• Lubricate the lock: Use a dry lubricant like graphite spray or powder to reduce friction and make it easier to remove the broken key. Oil-based lubricants like WD-40 can also work, but they may cause issues with the lock later on.
• Use tweezers: If part of the key is sticking out of the lock, you can try to pull it out with tweezers. Make sure the tweezers are thin enough to fit along the sides of the key without pushing it further in.
• Use a magnet: If your keys are made of a magnetic material, such as iron or steel, you can hold a magnet close to the lock to attract the broken piece and pull it out.
• Use a key extractor kit: Insert a key extractor tool into the lock and turn it slightly to hook onto the broken key. Then, pull gently to remove it. You can also make your own extractor from a small jigsaw blade.
• Dismantle the lock: If you have some DIY know-how, you might be able to dismantle the lock to remove the broken key.
• Glue the key back together: Apply gel-type glue to the part of the key that's stuck and use a metal wire or toothpick to stick the pieces back together. Be careful not to push the broken part further into the lock.
• Call a professional locksmith: If all else fails, a locksmith will have the skills and equipment to solve the problem without damaging the lock.

Adjust the strike plate to realign the latch bolt

If your door lock isn't working properly, it may be that the strike plate is misaligned. This can happen when a wood-frame house settles and shifts over time, causing the door frame to move out of square. The latch bolt may no longer line up with the strike plate, making it difficult to lock the door.

To fix this, first, ensure all the hinges are tight. Loose screws can cause a door to sag, resulting in the latch bolt missing the strike plate. If tightening the screws doesn't work, try the following:

Adjust the Strike Plate:

• Open the door and apply chalk or lipstick to the end of the latch bolt.
• Turn the knob to retract the latch, close the door, and release the knob so the latch touches the strike plate.
• If the mark is too high, tighten the bottom hinges. If it's too low, tighten the top hinges. For minor misalignments, tightening all the hinges may solve the problem.
• If tightening the hinges doesn't help, measure the misalignment of the mark on the strike plate.
• If the latch is off by 1/8 inch or less, remove the strike plate and enlarge the hole slightly with a file.
• If the mark is more than 1/8 inch above or below the hole, you'll need to reposition the strike plate. Use a sharp chisel to enlarge the indented section.
• Hold the strike plate in the new position and drill new 1/16-inch holes for the screws.
• Fill the gap in the indented section with wood filler after moving the strike plate.
• Screw the strike plate tightly into place and test the door.

By following these steps, you should be able to realign the latch bolt with the strike plate, ensuring your door lock functions properly again.

Replace the lock if it's beyond repair

If your lock is beyond repair, you may need to replace it. This can be done by following a few simple steps and will ensure your door security is not compromised.

First, you need to measure the space where you will install the replacement lock. Measure the diameter of the holes in your door and select a new lock that fits those dimensions. Older homes may pose a problem with matching the size. If you need to create new holes or enlarge existing ones, you can purchase a hole saw set. Alternatively, make your own guide by cutting a hole in a piece of scrap wood and clamping it over the hole.

The typical diameter for the hole connecting the two doorknobs is 2 1/8 inches, but it is always best to check. You should also measure the distance from the edge of the door to the centre of the hole, known as the setback. This is usually either 2 3/8 inches or 2 3/4 inches.

Next, you need to remove the old door knobs. Depending on the style of your lock, you may need to remove the knobs to replace the lock. There may be a set screw under the knob that can be removed with an Allen key. If not, look for a small hole that will receive a pin or paperclip to release the latch. Repeat this on both sides if necessary.

Now, remove the cover plates. These can be tricky to remove, but look for a small depression or slot around the edge of the cover plate where it meets the door. Place a wood shim against the slot and slide the tip of a flat screwdriver into the slot, twisting to pop the cover loose.

The next step is to remove the screws from the old lock. There are several sets of screws to consider: those holding the knobs together, the latch in place, the deadbolt in place, and the strike plate and deadbolt plate into the jamb. Once these are removed, the knobs will come off, and you can take out the latch and deadbolt.

Now you are ready to replace the latch and deadbolt with new ones. Ensure the holes are free of debris, then install the latch first, with the tapered side facing the direction you will push the door to close it. Press it into the recess and tap lightly to seat it against the door. Secure it with screws.

The deadbolt follows the same procedure but without a rounded face and without adjustments. Secure it with screws.

Finally, install the new lock's knobs or handles. If the knobs need to be removed from the lockset, do so now. Slide the knob with the key tumbler into the hole so that its lever slides into the latch's square gear. Slide the interior side of the knob on so that it sits flush against the door. Align the interior knob's plate with the exterior knob's screw holes and thread the machine screws into the screw holes to hold the knobs together loosely. Position the lockset so that it is centred over the knob hole, straight, and covers the entire hole. Tighten the screws securely.

If necessary, install the cover plates over the lockset and install the knobs. Remove the shims and check that the key and knob work before closing and latching the door.

Frequently asked questions