What is a Auto-Reverse Mechanism?
A safety feature that causes the garage door to automatically reverse direction if it contacts an object while closing.
The auto-reverse mechanism is a critical safety feature required on all garage door openers sold in Canada and the United States since 1993 (mandated by UL 325 safety standard). It consists of two systems: (1) mechanical auto-reverse — if the closing door contacts a solid object, a pressure sensor in the opener detects the resistance and immediately reverses the door; and (2) photoelectric auto-reverse — infrared photo-eye sensors mounted 6 inches above the floor on either side of the door opening create an invisible beam. If anything breaks the beam while the door is closing, the door stops and reverses. Both systems must be functioning properly at all times. Testing the auto-reverse should be part of every monthly homeowner safety check (place a 2x4 board flat on the ground under the door and close it — the door must reverse upon contact).