Many years ago one of my first customers was a fast food restaurant chain here in south Florida. One morning I received an emergency call from one of the managers, he could not open the restaurant door to open for business. I was told the deadbolt unlocked and the key turned in the door knob but the door would not open.

This job site was not close. I was at least 50 minutes away on a good day with no traffic. I made better than average time and found two managers sitting outside waiting for me to arrive.

I put the key in the deadbolt lock, it was unlocked. I put the key in the door knob and turned the key. Since the door opened out I could see the latch fully retracting. The door was unlocked. I pulled on the door but the door would not move. So I pulled harder, the locks were clear so something else was holding the door closed. The door moved a little. I pulled as hard as I could and the door opened.

I inspected the door frame for rubbing but the door was now working normally. I noticed some small round stones lying by the threshold of the door.  I could see deep scratches in the stones. I concluded that somehow the small stones got wedged in the door threshold, creating the illusion the door would not unlock.

Recently I was called out to a private school. The exit/entry door from an administration area would not open. When I first saw the door nothing appeared out of place. I tried to press down on a push paddle which retracts a latch and allows the door to open. The paddle was stuck solid in place. I also noticed the door did not have the usual in/out play many doors have for expansion and contraction. The whole door was tight, like something was wedged in the door frame.

The door was a large glass door with a push bar across the glass. The push paddle used for opening the door was below the crossbar. I managed to pull on the crossbar with both hands while simultaneously pressing the push paddle in with my knee. The door opened and immediately I found the culprit responsible for jamming the door against the threshold; ground up wood chips, better known as mulch.

If doors suddenly start acting strange, like not closing and latching, or not unlocking, check the door frame and threshold for debris. The lock problem you think you have may be totally unrelated to the lock. A very common problem is the door rubbing the door frame because the janitor wedged the door open by jamming his broom handle in the top hinge. I see have seen this problem many times.