Auto-reverse and photo eyes: what the federal rule requires

16 CFR Part 1211 is the federal safety standard for automatic residential garage door openers. It applies to openers manufactured on or after January 1, 1993 for sale in the United States, and it incorporates parts of the UL 325 standard by reference.

• Built-in reversing. Section 1211.7 says a closing door must start to reverse within 2 seconds of contact with an obstruction, except in the first foot of travel from fully open.
• A second safeguard. Section 1211.6 requires one more layer: a wall control you must hold down to close the door, a connection for an external device such as photo eyes, or a built-in secondary sensor.
• Self-checking. Section 1211.8 says the opener must check for the external device on every close cycle. If it is missing or faulty, a closing door must open, and an open door must not close more than 1 foot below the top.

The CPSC adds that reversing systems have been required on openers made or imported for U.S. sale since January 1, 1991, and the external entrapment requirement was added in 1993.

The federal rule leaves exact height to the manufacturer. LiftMaster's 8010 manual says to install the sensors so the beam is no higher than 6 inches above the floor. DASMA says the same, and the CPSC gives 4 to 6 inches.

This is how LiftMaster's manual describes it. Its manual says to run this test every month.

1. Open the door fully.
2. Lay a 1 1/2 inch board, or a 2x4 laid flat, on the floor centered under the door.
3. Close the door with the remote.
4. The door must reverse when it touches the board.

If the door stops on the board but does not reverse, LiftMaster's manual describes a travel adjustment and says that if the opener keeps failing, call a trained door systems technician.

LiftMaster's version: open the door, set the opener box (or a similar object) in the door's path, and press the remote to close. The door should move no more than an inch, and the opener lights should flash. DASMA's version: wave an object through the beam as the door closes. The door should not close unless someone holds the wall button down the whole time.

The CPSC says to disengage the opener until it is adjusted per the owner's manual, repaired or replaced. Use the door by hand only if it moves freely and stays put when you stop it partway.

One more thing to know: LiftMaster's manual warns that an improperly balanced door may not reverse when required. Balance is set by the springs, which are under high tension. Do not adjust springs, cables or bottom brackets yourself. Book a sensor alignment or a balancing visit, or schedule an appointment. Same-day appointments are available.