Comment · Thu, April 18, 2013
TIL that in most elevators, the close-door button doesn't work. It's just a placebo. Press away, friends.
What they were answering
GottaP · 262 points
Elevator mechanic here- they work.
If you arrive at a floor in the direction you are travelling and no one is there, or you mistakenly registered the wrong call, stick your hand or your leg in the entrance momentarily as to "break the beam" of the infrared door detector. The controller for the elevator is looking for that signal ie- someone entering or exiting. Once the beam is broken, door time is cancelled therefor allowing the door close button to function.
u/MisterYouAreSoDumb
Although in Mexico City, if you hit that close button that door slams shut instantly! No need to break the infrared beam. That's where you are safest from a zombie attack!