Photo Eye Repair and Alignment

The Two Sensors That Decide Everything

Near the floor at either side of your garage opening are two small sensors. One sends an infrared beam, the other receives it. If that beam is broken while the door is closing, the door stops and reverses.

They have been required on residential openers since 1993 under UL 325, and they are the reason a garage door will not close on a child.

What Goes Wrong

Alignment. The most common by far. They must face each other squarely, and a knock from a bike handlebar, a bin, or a broom is enough. The brackets are thin steel and bend easily.

Obstruction. The beam sits low, around six inches off the floor, which is exactly the height of ordinary garage clutter. A bag, a coiled hose, a bin edge, a cat.

Dirty lenses. Dust films and cobwebs. A wipe with a soft cloth resolves a surprising number of these.

Sun. Low afternoon sun shining directly into the receiving sensor swamps the beam. A classic seasonal complaint, fixed with a small shield or a slight repositioning.

Wiring. The wires run along the floor line where they get pinched, stapled through during other work, chewed by rodents, or corroded. Near the water a green crusted splice is a routine find.

Actual sensor failure. Real, and the least common item on this list.

Reading the Lights

Most systems use two indicators. One sensor shows a steady light meaning powered. The other shows a light that goes out or blinks when the beam is broken.

A blinking light usually means alignment or obstruction. No light at all on one sensor points at wiring or power. Both steady with the door still reversing means the problem is somewhere else entirely.

Worth knowing: the sensor that is blinking is often not the one that moved. It is reporting that it cannot see its partner.

Height Matters

Sensors are meant to sit no higher than six inches above the floor.

We find them zip-tied halfway up the wall regularly, usually to clear storage or stop them being knocked. At that height they will happily miss a toddler sitting in the doorway, which is the exact scenario they exist for. We reset them, every time.

What We Test Before Leaving

Beam-break reversal, then contact reversal with a two by four laid flat on the floor. Both must work.

Call Hugsnoslugs at (562) 497-2929.