If you have small children or even have had overnight guests I’m sure that you have experienced one of your bedroom or bathroom doors being locked. It happens more often than you think and sometimes calling a residential locksmith is unnecessary when you know how to do it yourself. If your home has several interior doorknobs with keyed locks or even the push button kind there are helpful hints on how to unlock them on your own.
If you have a push-button doorknob, all you need is a paper clip to put into the small hole to open the locking mechanism. You can also use a butter knife in cases where the knob has a slit-type groove on the exterior of the handle. Once that is done, turn the knife or other preferred tool clockwise. Some may require you to turn counter-clockwise; it all depends on the installation.
Keyed Door Lock
When you have a keyed door lock it is a little bit harder to open but it is possible. One simple method is to simply use a paperclip and tension wrench or a small key which is almost the same measurements of the paper clip. Apply pressure to the end of the clip to make it as flat as possible.
Place the forged end of the paperclip in the upper area of the tension wrench and push until you get resistance. Then push on the pin with the paperclip to try to move it out of the way so the tension wrench can move a little. Repeat the procedure on each pin until the lock opens. You have to repeat the steps a number of times but eventually it should unlock your door.