Garage Door Won't Close? It's Probably the Sensors.
The door goes up fine, but press the button to close and it either sits there or drops a foot and pops back up while the opener light blinks at you. Mo here. That blink is the opener telling you exactly what's wrong, and most of the time you can fix it in the next ten minutes without a single tool.
“Whatever you do, never wire around the safety sensors or tape them together to make the door close. Those eyes are the only thing standing between the door and whatever's under it, a paw, a foot, a kid chasing a ball. Fix them. Don't silence them.”. Mo
Direct answer
A door that won't close is almost always a sensor problem.
A garage door that opens fine but won't close usually has a safety sensor issue: something in the beam's path, sensors knocked out of alignment, dirty or fogged lenses, or afternoon sun blinding one eye. The two sensors sit about six inches off the floor, one shoots an infrared beam to the other, and if that beam breaks, the opener refuses to close from the remote and flashes its light. Here's the one-minute proof: press and HOLD the wall button until the door is all the way down. If it closes while you hold the button but not from the remote, it's the sensors, one hundred percent. If it won't close even then, skip to checks 06 through 08.
Start at 01. Stop when it closes.
Checks 01 through 05 are sensor checks, and they solve most stuck-open doors without a tool. Checks 06 through 08 are for doors that reverse partway down. Work in order and stop the moment the door behaves.
Look at the sensor lights.
Crouch down by the two little eyes near the floor, one on each side of the door, about six inches up. Each should show a steady light. Most brands run one steady light on the sending unit and a second light on the receiving unit that only holds steady when the beam connects. A blinking or dark light on the receiving side means the beam is blocked, the sensors are out of line, or a wire is loose. Steady lights on both? The sensors are happy, skip ahead to check 06.
Clear the sensor path.
The beam is an invisible tripwire across the whole doorway, and it only takes one thing in the way. Leaves blown against a lens. A bike wheel. A trash can rolled two inches too far in. A cobweb swaying in the beam counts too, the sensors are that sensitive. Clear everything out of the door opening, floor to about a foot up, and try the remote. This one fixes more doors than any other check on the page.
Re-square knocked sensors.
Each sensor sits in a little bracket, and those brackets get kicked, bumped by bikes, and whacked by weed eaters all summer. The two lenses have to point straight at each other across the doorway. Loosen the wing nut, gently swivel the sensor until its light goes steady, and snug it back down. If the bracket itself is bent, ease it back by hand. You'll know you've got it when both lights hold steady with nothing in the doorway.
Wipe the lenses.
Georgia pollen season paints everything yellow, and that includes sensor lenses. A film of pollen, dust, or spider silk scatters the infrared beam enough that the receiver loses it. Wipe both lenses with a soft dry cloth, no cleaners needed, and brush away any webs behind the brackets. Spiders love the warmth of that little LED. Two swipes of a rag has ended a lot of sensor trouble around here.
Blame the afternoon sun.
West-facing garage? If the door refuses to close at the same hour every afternoon and behaves the rest of the day, the low sun is flooding one sensor's lens and drowning out the beam. The polite fix: slide a short shade tube, even a piece of half-inch pipe or rolled cardboard, over the receiving lens like a lens hood. Or swap the sending and receiving sensors so the receiver faces away from the sun. Either trick ends the daily standoff.
Check the track for obstructions.
If the door starts down fine and reverses when it touches something, the sensors aren't your problem. Look in both tracks for anything wedged in: a stone, a rake handle, ice in winter. Then sight down each rail for bends or dents that pinch the rollers. A door that reverses on contact is doing its job, it thinks it hit something. Clear the tracks and look at where the door stops; whatever is there is your answer.
Suspect the travel and force limits.
Openers are set to expect the floor at a certain distance. Those settings drift with age, and when the opener thinks the floor is higher than it is, it touches down early, assumes it hit an obstacle, and reverses. Same story if the door stops shy of the floor. Adjusting the limit and force screws is owner's-manual territory, small turns only. One wrong turn and the door slams down hard, and forced-close pressure is how doors damage cars and worse. If the manual is long gone, call us instead.
Feel for binding rollers and hinges.
If the door shudders, groans, or stutters on the way down and then gives up and reverses, worn rollers or dry hinges are binding in the track. The opener reads the extra resistance as an obstruction. Watch the rollers as the door moves: wobbling, grinding, or flat spots mean they're done. That's a quick, inexpensive fix on our end, and it's exactly what our roller repair crew does all day. A binding door also chews up the opener, so don't let it grind for months.
The “while we're here” opener.
I've followed behind outfits that turned a knocked-over sensor into a brand-new opener. The tech confirms it's the sensors in thirty seconds, then tells the homeowner the whole unit is “on its way out” and, while we're here, why not upgrade? A sensor pair is one of the cheapest parts on the door. An opener is not. Selling the second one to fix the first one isn't a repair. It's a shakedown with a ladder.
When you call Mo Better
Tell us which check it failed, and we'll finish the job, usually the same day.
Phones are answered 24/7 by a real person at (770) 588-1037. Tell them the door opens but won't close and which check numbers you already ran; that genuinely speeds up the visit. The tech confirms the diagnosis in your driveway and quotes in writing before touching a wrench. Sensor swaps and limit adjustments are quick work. If the real culprit turns out to be the motor or the logic board, that's opener repair. If the door is grinding because nothing's been lubed since it was hung, a maintenance visit resets the clock on the whole system. And if the door is stuck wide open at midnight with your garage full of tools, the emergency line runs around the clock. Nobody should sleep with the garage hanging open.
Why does my garage door start to close then go back up?
How do I know if my sensors are bad versus the opener?
Can I bypass the safety sensors so the door will close?
Why does my door only act up in the afternoon?
Does rain or humidity make garage doors stop closing?
Still won't close? We close them for a living.
You cleared the beam, squared the sensors, wiped the lenses, and the door still pops back up. Fine. That's exactly what we're for. A real person is on the line right now, and before-11am calls usually get a same-day truck.
"Mo Better Garage, we make it waaaay 'mo better."
