If the key won t go into the lock ask yourself if the weather is cold enough for the lock to be frozen.
Key not going into door lock.
Key will not work if you ve had a new spare key cut recently it could be a poorly cut key causing the problem.
As small as a lock might seem it is more than common to find things inside the lock resisting the key from going in all the way.
Once it s out use a fine file to.
If this is the case your bent key is trying to fit into a straight lock and it just won t work.
Blow strongly in the lock and put wd40 or graphite inside but not both.
It may have been tampered with if the plug was rotated substantially.
A dry graphite lubricant will lubricate the inside of the lock making it easier to unlock.
Lubricating the lock with non destructive oil i e.
Outdoor locks can collect a lot of dirt and dust inside the lock.
What to do if your house key won t turn in the lock spray the lock with lubricant to remove dirt and dust.
Hold the application straw right above your stuck key aiming it into the hole.
This might be difficult to inspect on your own.
Remove it gently with a piece of steel wire a small guitar string for example.
Warping if the door cannot physically lock due to the frame or door being warped an adjustment of the strike plate could rectify the problem without the need of a new lock.
Try to see if you can rotate the plug back to it s proper locked position with something.
Not wd 40 may help.
When to call a locksmith.
Debris inside the lock.
If it is hold the key with a heavy glove and heat it with a match or lighter and then work it gradually into the keyway.
In the future keep a lock de icer on hand.
Have you had a new cylinder fitted.
Try to insert gently the key and apply some.
Assuming the door lock is hard to unlock with a key because it is dirty or gunked up inside and not damaged your best bet is to use a dry graphite.
If your key will only go into the lock partway there may be an obstruction blocking it.
Repeat heating and inserting the key until the ice has melted.