How does LiftMaster ensure the security and reliability of their system?

Per UL325, the LiftMaster solution must be fail-safe.  Any feature using the unattended operation (e.g., Timer to Close or Remote Closing) must end in a fail-safe mode in accordance with UL requirements. 

This means that the garage door operator will try twice to close the door using unattended operation. If something stops the door’s motion or reverses the door’s direction (e.g., the door is blocked, photo eyes are blocked, etc.), the door will revert to the open position.