Garage Door Won't Close? 7 Causes & Fixes

Garage Door Won't Close — 7 Common Causes and Fixes

A garage door that refuses to close is more than frustrating — it's a security risk and, in hot weather, an energy efficiency problem. Before you call for service, work through these seven common causes. Several can be fixed in minutes without a technician.

1. Safety Sensor Misalignment (Most Common Cause)

Garage door openers built after 1993 are required by law to have photo-eye safety sensors mounted near the floor on each side of the door. These sensors beam an invisible light across the door opening. If something blocks the beam — or if the sensors are misaligned — the door will refuse to close.

How to check: Look at both sensor units near the bottom of the door tracks. They typically have LED lights. One sender (usually glowing steadily) and one receiver (usually blinking if misaligned, steady green if aligned).

Fix: If the receiver LED is blinking or off, the sensors are misaligned or blocked. Clean both lenses with a soft cloth. Then loosen the sensor mounting screw, adjust the sensor until the LED glows steadily, and retighten.

2. Something in the Door's Path

This sounds obvious, but it's easy to miss. A trash bag, kid's toy, or even a leaf pile near the sensor or in the door's path can trigger the safety system.

Fix: Clear the door's full travel path. Make sure nothing is on the floor under the door, and check that nothing is leaning against the door or the tracks.

3. Damaged, Bent, or Dirty Safety Sensors

If the sensor lenses are dirty, cracked, or spider-webbed, they won't transmit or receive the signal properly. Sensor damage is also common from being hit by a vehicle bumper or lawn equipment.

Fix: Clean the lenses. If damaged, replace the sensor pair — they're typically sold and replaced as a matched set. This is a straightforward repair that most technicians can complete in under 30 minutes.

4. Down-Limit Switch Needs Adjustment

The down-limit switch tells your opener where "fully closed" is. If this switch is set incorrectly — too far above the floor — the opener will try to close, think it's already down, and stop short. The door reverses or stops without fully closing.

Fix: Consult your opener manual for the down-limit adjustment procedure. It's usually a small screw on the side of the opener unit. This is a DIY-possible fix, but if you're not comfortable, a technician can do it in 15 minutes.

5. Broken Tension Spring

A broken torsion or extension spring doesn't just prevent the door from opening — it can prevent it from closing properly too. Springs counterbalance the door's weight; without them, the opener struggles or fails entirely.

Signs: You heard a loud bang (spring snap), the door looks or feels crooked, or one side of the door moves faster than the other.

Fix: Call a technician. Do not operate your door with a broken spring. Spring replacement is a job for a professional.

6. Interference from Another Remote

Older 9-switch or 12-switch dip-code remotes and openers can sometimes receive interference from a neighbor's remote on the same frequency. You may see the door start to close and then reverse, or refuse to respond to close commands.

Fix: Test without any remotes — use only the wall button. If it closes with the wall button, the issue is likely remote frequency interference. Reprogram or replace the remote, or upgrade to a rolling-code opener (more secure and immune to this problem).

7. Opener Travel Adjustment or Mechanical Issue

If none of the above applies, there may be a mechanical issue with the opener itself or the door hardware. A binding track, worn roller, bent section, or failing opener gear can all cause the door to stop before it fully closes.

Fix: Inspect the tracks for obvious bends or debris. Try lifting the door manually to check for binding. If there's mechanical resistance, don't force it — call a technician to identify and fix the cause.

When to Call a Professional

If your garage door still won't close after checking the sensors, clearing obstructions, and checking the down-limit, call a professional. Real Gate & Garage Door provides same-day garage door repair throughout the San Fernando Valley.

(818) 915-5715 — available 7 days a week.