Garage Door Will Not Close? Work Through This Before You Call

Published August 20, 2026

The door starts down, then reverses and goes back up. Sometimes the opener light flashes. Most of the time you can fix this yourself in five minutes.

First, Understand What Is Happening

Your door is not broken. It is refusing.

Since 1993 every residential opener has been required to carry entrapment protection, and one half of that is a pair of photo eye sensors sitting near the floor at either side of the opening. One sends an infrared beam, the other receives it.

If that beam is broken at any point while the door is closing, the opener reverses. That is correct behaviour, and it is why a garage door does not close on a child.

So the question is not “how do I make it close” but “what is breaking the beam, or making the opener think something is”.

Work Through This In Order

1. Look for something in the beam

The beam is about six inches off the floor, which is exactly the height of ordinary garage clutter. A bin edge, a bag, a coiled hose, a broom leaning against the wall, a cat sitting in the sun.

Clear the whole floor area near the opening and try again. This is the single most common cause.

2. Read the sensor lights

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

• One blinking: alignment or obstruction.
• No light at all on one: power or wiring to that sensor.
• Both steady but the door still reverses: probably not the sensors. Skip to step 6.

A detail worth knowing: the sensor that is blinking is often not the one that got knocked. It is telling you it cannot see its partner.

3. Check alignment

The sensors must face each other squarely across the opening. The brackets are thin steel and bend if a bike handlebar catches one, or if someone sweeps enthusiastically.

Loosen the wing nut, sight along one sensor toward the other, adjust until the indicator settles, and tighten. Do one at a time so you always have a reference.

4. Clean the lenses

Dust films, cobwebs, and in a coastal garage a fine salt haze. A soft dry cloth on both lenses takes ten seconds and fixes more of these than people expect.

5. Consider the sun

If this only happens in the late afternoon, low sun is shining directly into the receiving sensor and swamping the beam.

It is a genuinely common seasonal complaint. The fix is a small shield, a piece of tape as a hood, or repositioning the sensor slightly.

6. Test whether it is the sensors at all

Here is the diagnostic that saves people money.

Hold the wall button down continuously. Holding it overrides the photo eye protection and forces the door to close.

• If it closes: the mechanics are fine and your problem is electrical, in the sensors or their wiring.
• If it still reverses: it is not the sensors. Something else is going on.

Do that once as a test. Do not use it as a workaround.

When It Is Not the Sensors

It reverses partway down rather than at the bottom. That usually means the door is binding on something. A worn roller, a bent section of track, or a door running out of square. The opener meets resistance, decides it has hit an obstruction, and reverses. Correctly.

Close force set too tight. The opener’s force limit is adjustable, and if it is set too fine the door reverses on normal friction. Adjustable, but only once you are certain the door is not actually binding.

The door is heavy. If the springs have lost tension the opener is doing work it was never meant to do, and it may hit its limit partway. Pull the manual release and lift the door by hand: it should be liftable and should hold position at waist height.

The One Thing Not to Do

Do not twist the sensor wires together to bypass them.

It gets suggested online, it works in the narrow sense that the door will close, and it removes the only automatic protection preventing that door from closing on a child, a pet, or you.

These sensors became mandatory because of what happened before they existed. If a door will not close there is a reason, and the reason is nearly always cheap.

While You Are Down There

Test the other safety system too, since almost nobody does.

Lay a piece of two by four flat on the floor in the door path and let the door close onto it. It should touch and immediately reverse. If it does not, the contact reversal or the force setting needs attention, and that is worth a call.

Also check the sensor height. They should sit no higher than six inches above the floor. We regularly find them zip-tied halfway up a wall to clear storage, and at that height they will miss a small child entirely.

What to Say If You Do Call

Three answers save everyone time: what the sensor lights are doing, whether it closes when you hold the wall button, and whether it reverses at the bottom or partway down.

With those we can usually tell you the cause on the phone, and a fair number of these we talk people through for nothing.

Call Hugsnoslugs at (562) 497-2929.