Remove the old lock.
Home front door lock wont unlock at all.
The lock cylinder may be broken so that you cannot use your key or anything else to move your door lock into the unlocked position.
That can cause the pins to get stuck in a partially raised position and prevent the plug from turning.
Don t use a wet.
Flip the key and open the door.
Spray the door key with a graphite based lubricant.
You can spray a little dry lubricant in the lock to free up the plug so you can open the door.
If the key turns but doesn t unlock the lock disassemble the lock so that you can be sure the cam or tang is properly engaged with the bolt.
Outdoor locks can collect a lot of dirt and dust inside the lock cylinder.
Slide the key in the lock and tap lightly on the key to lubricate the inside of the lock.
Misaligned deadbolts and latches are common door lock problems.
A strike plate is usually affixed to the door jamb and facilitates the extension of the bolt or latch.
Lubricate the moving components with graphite then replace any broken parts and reassemble the lock.
If that is the problem it is easy to fix.
If the malfunctioning lock is in the door handle there will be at least two screws securing the door handle to the door.
This video shows how to disassemble and lubricate a basic cylindrical doorknob.
The same solutions apply to when you are solving the issue with most broken locks.
In most cases it means that the latch or locking bolt are not lining up with the door locks strike plate.