Garage Door Won't Close? The Usual Causes and Fixes
When a garage door won't close — or reverses right back up — the cause is usually the safety sensors. Here's how to troubleshoot it yourself, step by step.
When a garage door refuses to close — or starts down and immediately rolls back up — it's tempting to assume the opener is broken. It almost never is. Modern openers are built around a safety system that errs on the side of not closing, and that system is the cause the vast majority of the time. Here's how to work through it.
First, understand why it reverses
Since the early 1990s, garage door openers are required to have photo-eye sensors: two small units mounted a few inches off the floor on each side of the doorway, facing each other. One beams an invisible infrared signal to the other. If anything breaks that beam while the door is closing — or if the opener thinks something has — it reverses the door so it can't crush a child, pet, or car.
So a door that won't close is usually the opener protecting you. The fix is almost always at those sensors.
1. Clear the doorway and check the sensors
- Remove anything in or near the opening — a trash can, a stray cord, a leaf pile, even a spider web across a lens can break the beam.
- Look at each sensor's indicator light. Most have a small LED; when the beam is properly aligned and unobstructed, both glow steady. A blinking or dark light points you straight to the problem sensor.
2. Clean and realign the sensors
This is the single most common fix.
- Wipe both lenses gently with a soft, dry cloth — dust, grime, and condensation are enough to blind them.
- Realign them. A bump from a car door or a ladder can knock a sensor off-aim. Loosen the wing nut or bracket and adjust the sensor until its indicator light stops blinking and glows steady, then retighten. Both sensors must point directly at each other.
3. Check the sensor wiring
If cleaning and aligning don't restore steady lights, follow the thin wires from each sensor back toward the opener. Look for wires that are pinched, cut, chewed, stapled through, or loose at the terminals. A broken sensor wire reads the same as a blocked beam.
4. If the sensors are fine: force and travel settings
If both indicator lights are steady but the door still reverses, the opener's close-force or travel-limit settings may be off — for example, set so sensitive that normal resistance reads as an obstruction, or a down-limit that makes the door hit the floor and bounce back. These are adjustable screws or buttons on the opener; your model's manual shows the procedure. Adjust in small increments.
5. Look for a physical obstruction
A door that stops partway and reverses may be hitting something real:
- A bent or misaligned track.
- A worn or broken roller binding in the track.
- Debris in the track's path.
Inspect the tracks and rollers, and keep the hardware moving freely with the lubricate garage door springs and rollers task. A door that's gone heavy or jerky can also mean a spring problem — check it with the test the garage door balance task.
A safety note: never disable or bypass the photo-eye sensors to force a door closed. They're the feature that prevents the door from crushing someone. If they're faulty, fix or replace them — don't defeat them. And leave torsion-spring repairs to a pro; those springs are under enormous tension and cause serious injuries.
Keep it from happening again
Most garage-door no-close calls trace back to neglected sensors and hardware. Regular upkeep — testing the safety reverse, lubricating the moving parts, and checking the balance — keeps the door reliable. See the garage door maintenance guide, the test garage door auto-reverse & sensors task, and the garage door system overview.
Make it automatic
Build your free Owner Tools plan and we'll schedule the sensor/auto-reverse test, lubrication, and balance check that keep your garage door closing on the first try. No login, no address required.