Getting home after a long day to find that your key no longer opens your front door can be an exasperating experience, to say the least. Fortunately, identifying the problem as quickly as possible can help you get inside sooner and protect your locks from future malfunctions. We’ll outline some of the most common causes of lock failures, and the simple methods you can use to address them.
In some cases, a broken lock isn’t broken at all. Try a spare key — if it works just fine, the key itself might be broken. If this is the case, you should make a copy from the spare and discard the old master. If your original key is the only existing version, however, you will need to re-key the door.
Your key may also break off in the lock, especially if you use excessive force or depend on a key made of lower quality material. To remove the broken piece, use needle-nose pliers or part of a coping saw-blade. You may also be able to push the fragment out with a stiff wire after removing the lock cylinder.
If neither a spare nor the original works, your lock may be jammed. You can use a stiff wire or hairpin to prod the keyhole under the pins and feel for a blockage. Dirt and debris may also keep the pins raised, allowing the key to turn but not to unlock the door.
Use a dry lubricant such as graphite or WD-40 in the lock and on the key, turning the key a few times until you can coax the lock open. Once you’ve gained access, you can also disassemble and reassemble the lock to check for broken parts and further clean the interior.
If temperatures are low enough, your lock may freeze. This can be remedied by heating up the lock or the key with a match or a lighter while wearing a heavy glove. Keeping lock de-icer on hand, especially if you live in an area prone to freezing temperatures, may also be useful.
A brand new key can also offer trouble on the first few tries, due to rough spots that don’t quite match up with the pins in the lock. You can hold the key over a candle until parts of it are blackened by soot, and then try turning it slightly in the lock. After removing it, you will see shiny areas where the soot was. Filing down these areas will remove the rough spots on the key, allowing it to unlock the door more easily.
Are you able to get the door open, but only after a lot of effort? Try turning the key in the lock with the door open — if this works fine, there may be a problem with the strike plate, which prevents the deadbolt from making proper contact. If you can’t turn the key even with the door open, you should clean and lubricate the lock and key with graphite or another dry lubricant.
There are a number of precautions you can take to prevent these issues. Always insert the key with care, and don’t force it — even if you’re in a rush. Always make sure you’re using the right key — it’s easy to mindlessly force the wrong key in the door, breaking the key or the lock in the process. Make sure your spare keys are made of high-quality materials that are not easily bent, and test them all before you need to use them.
A bit of creativity and persistence can generally go a long way when it comes to repairing a faulty lock or key. If you’re facing repeated difficulty, however, don’t hesitate to contact your local locksmith.