Sliding doors usually separate patio or deck areas from the inside of the home. You may also have sliding doors separating dining areas from living areas or bathrooms from the rest of the house. Troubleshooting the lock on your sliding door will allow you to try to restore it to full working order without the need for a locksmith. Most sliding door lock issues can be solved at home without special tools.
Ensure you are using the correct key in the lock. You may have multiple keys for different sliding doors in your home that have are easily confused. Make sure you are turning the key in the correct direction. The barrel may turn from right to left or left to right depending on the way your sliding door was installed.
Verify that all the locks on the door have been released. Sliding doors that lead to outside areas usually have more than one lock for additional security. Examine the top and bottom of the door for extra bolts that need to be released.
Spray a suitable penetrating oil inside the lock. Older locks can rust or seize when not in use, preventing the key from releasing the lock. Penetrating oil is available from most hardware stores.
Ensure that the door is free of ice and snow. Sliding doors and windows are easily frozen shut during the cold winter months and can be extremely difficult to open. It is better to wait for a sunny day to melt the ice rather than to try to force the door open.