Why does my garage door reverse before closing?

Federal law has required these photo-eye sensors on every opener since 1993, so almost any door reversing on its own is the safety system doing its job, even when nothing is actually there.

Check the safety sensors first

The two small sensors sit about six inches off the floor on each side of the door. One sends an infrared beam, the other receives it. Break that beam and the door reverses. Walk through this before anything else:

• Look at the indicator lights. Both sensors have a small LED. A steady light on each usually means they're aligned. A blinking or dark light points to a problem.
• Wipe the lenses. Dust, cobwebs, or condensation on the little lens fools the sensor. A soft dry cloth often fixes it.
• Clear the path. A trash can, a coiled hose, or even a stray leaf can break the beam.
• Check for sun glare. Late-day sun shining straight into the receiver can mimic a blocked beam.

If wiping and clearing don't help, the sensors are likely out of alignment, which is the next thing to rule out.

When the garage door reverses before closing because of alignment

Sensors get bumped out of position by a stray ball, a car door, or a kid's bike. When they no longer point straight at each other, the beam misses and the door reverses before closing every time.

To realign them, loosen the wing nut or screw holding one sensor, aim it directly at its partner, and tighten when both LEDs glow steady. A simple trick is to run a string line between the two brackets to confirm they sit at the same height and angle. If the wiring is pinched, frayed, or chewed by a rodent, the sensors lose contact and behave the same way.

How to tell sensor trouble from a force problem

Here's a quick way to narrow it down. Watch the door as it reverses:

• It reverses the instant it starts down, before moving far: almost always a sensor or wiring issue.
• It travels most of the way down, then bounces back up near the floor: more likely a close-force or travel-limit setting, or something physically catching the door low in its run.
• It reverses at the same exact spot every time: suspect a bent track, debris, or a flat-spotted roller at that point.

Matching the behavior to the cause saves you from adjusting the wrong thing. When in doubt, start with the sensors, since they cause the large majority of reversing-door calls and cost nothing to check.

Other reasons a door reverses

If the sensors check out, look at these:

• Close-force setting too low. Openers have a force adjustment screw. Set too sensitively, the unit reads normal friction as an obstruction. Small quarter-turn adjustments are safe; large changes are not.
• Worn rollers or dry tracks. Added drag makes the opener think it hit something. Fresh lubrication often solves it.
• A bent track or debris. A physical catch partway down stops the door and triggers the reverse.
• Travel limits off. If the opener thinks the floor is lower than it is, it reverses when the door touches down early.

When to call a pro

If you've cleaned and aligned the sensors, cleared the track, and the door still reverses, stop adjusting the force screws. Over-tightening the close force disables the very safety feature that protects kids and pets, and it can mask a real mechanical fault. A tech can test the force, the sensors, and the logic board in one visit and set everything back to safe factory specs.

We handle these diagnostics daily across Denver garage door repair calls, and a misaligned sensor is often a same-day fix. If the opener itself is failing, our services page covers repair and replacement with flat-rate pricing and no diagnostic surprises.