As a homeowner, you should reset the opener to prevent outsiders from opening the door with a remote that's set to a Liftmaster default code. A simple procedure allows you to reset the opener for one or more remotes.
doorsill - the sill of a door; a horizontal piece of wood or stone that forms the bottom of a doorway and offers support when passing through a doorway. doorstep, threshold. 1  doorway, room access, door, threshold - the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close; he stuck his head in the doorway.
Definitions (2) 1. The horizontal member of the bottom of a window or exterior door frame. 2. As applied to general construction, the lowest member of the frame of the structure, resting on the foundation and supporting the frame. See also mudsill. Picture of sill.