HOUSTON GUIDE

Photo eyes on a Houston door that will not finish the close

The door starts down, the opener clicks, and the panels go back up. Small units on both jambs, a few inches off the slab, are supposed to see each other the whole way. In Houston they film over with humidity, take mud from a wet tire, and lose the beam in late sun on a south-facing opening. Cleaning them is fair. Defeating them is not. This page is the difference.

By Mike Maziarz · Sources checked October 6, 2026 · How we write these guides

What the eyes are for

Photo eyes are a close-direction check. If the beam breaks, the opener should reverse or refuse to close on its own. They do not lift the door, they do not balance the spring, and they do not know whether a cable is slack. A straight door that reverses with nothing in the opening is their kind of fault. A door that leans or will not rise is someone else's chapter. Keep that split, because people replace sensors for a spring problem and then still have a heavy door.

Each unit has a lens and, on most openers, a small indicator. One side sends and one side receives, though you do not need the labels to start. If an indicator flickers when you wave a foot through the beam, the pair is at least partly alive. If it never changes, you may have power, alignment, or a wire fault. Write down what the lights do before and after you wipe the lenses. That note is the whole diagnostic many visits need.

Clean lenses and a gentle aim

Turn the opener's power off at the cord or the breaker if you will be touching brackets, then wipe each lens with a dry cloth. Humidity leaves a haze. Pollen and sprinkler film do too. A bracket that a bumper kicked will point at the floor or at the panel instead of across the opening. Loosen only the bracket screw enough to aim the unit at its mate, then snug it. The lenses should face each other, at similar heights, clear of the door's travel. Do not strap them out of the way to gain parking room.

Sun is a Houston-specific nuisance on front-facing doors in Meyerland, Memorial, and similar lots where the opening looks south or west. The door may close in the morning and reverse before dinner. Shade the receiving lens with your hand while you stand outside the path, and see if the indicator steadies. A small hood the opener maker allows is a real fix. Raising close-force is not. If the door will not open at all, leave the eyes and read the page on a door that will not open. Sensors almost never block the upward trip.

Wires, water, and what not to splice in a hurry

The wires run from the eyes to the opener, often stapled along the jamb. A staple through the jacket, a weed trimmer at the bottom corner, or a flood that covered the low pair can open the circuit. Look for obvious damage without pulling the staples out. If floodwater covered the eyes or the opener, stop. Leave the opener off and unplugged. Drying a lens does not dry a motor that was submerged. Splicing wires with whatever is in a kitchen drawer is how a damp bay gets a short. That repair belongs to someone who will replace the run and test the reverse.

A GFCI that trips when the opener runs can be the eyes, the motor, or a wet box. Reset a dry GFCI once. If it trips again, leave it off and say so. Do not defeat the GFCI with an adapter. After ordinary rain, when the water never rose above the slab film, wiping the lenses is enough of a first step. After a storm that left a waterline, the storm rules win over the sensor rules.

Do not bypass the beam

Do not tape the eyes. Do not aim them at each other across a shorter path that no longer crosses the opening. Do not jump the terminals at the opener with a scrap of wire. Do not raise the close-force dial so the door finishes the trip through an obstruction. Those tricks are how a door closes on a child, a dog, or a bicycle. A constant-pressure close, if your manual describes one, is a temporary way to get the door down while you watch it, not a license to delete the sensors. If you cannot watch the path, leave the door up and secured another way.

Close-force exists so a binding door reverses. If the door needs more force than it used to, the hinges, rollers, or track are asking for help. The cost factors on what changes a repair bill include that hardware. A sensor-only visit is a small scope. A sensor visit that hides a seized roller is the wrong scope. Tell the company you wiped the lenses and the door still reversed, and whether you touched the force dial. Honesty there matters more than a guess about the brand of the eye.

When clean eyes still reverse the door

Alignment can look right and still miss by a small angle, especially if the jambs are out of parallel on an older opening. The indicators are the authority, not the eyeball. If they will not hold a steady clear signal, stop fiddling and call. A door that reverses only when the bottom seal meets the floor is often the travel limit, not the eyes. A door that reverses at a random height may be a wire that flexes as the panels move. Those are technician adjustments, not another turn of a dial you do not have the manual for.

Keep the maintenance habit narrow. The maintenance page puts lens cleaning on the same list as rust and lubricant, because a filmed eye is ordinary in this air. It is not a reason to take the opener apart. If the bracket is cracked or the lens is yellowed and cracked, replacement of the eye pair is a normal part. Match them to the opener the manufacturer supports. A random pair from a bin may light up and still speak a different signal.

What to ask the company

Ask them to test the reverse with a block in the opening before they leave, eyes connected, force left in a safe range. Ask whether they replaced the eyes, the wire, or only realigned the brackets. A verbal says the sensors are good is weaker than a demonstrated reverse. The questions on hiring a garage door company cover the written scope and the permit office if the work grew into a new door. A sensor alignment should not quietly become a new opener without a pause.

Tell them about sun if the failure is time-of-day, about a bumper if a bracket is bent, and about floodwater if the wires were wet. Tell them if a previous crew taped an eye. Untaping is part of making the door safe, even if the door then refuses to close until the real fault is found. An open door for one more night is a better outcome than a door that cannot see the child walking back in for a ball.