A garage door that won't close is more than an inconvenience — it's an open door to your home. The good news is that most causes are simple, and a few you can fix yourself in under ten minutes. Here are the seven we see most often in San Jose homes, starting with the most common.
1The safety sensors are misaligned or dirty
This is the culprit at least half the time. Every garage door built since 1993 has two photo-eye sensors mounted about six inches off the floor on either side of the opening. They shoot an invisible beam across the doorway, and if that beam is broken — or if the sensors can't "see" each other — the door refuses to close as a safety measure.
What to look for: most openers flash a light or blink a code when the sensors are the problem. Check that both sensor LEDs are lit and steady. If one is blinking or off, they're out of alignment.
The fix: wipe both lenses with a dry cloth, then gently adjust one bracket until both LEDs glow steady. Spiderwebs and dust are the usual offenders — and heading into the Bay Area's rainy season, moisture and condensation on the lenses become a common cause too.
2Something is blocking the door's path
Obvious, but worth checking before anything else. A trash bin, a bike tire, a stray extension cord, even a buildup of leaves along the bottom seal will trip the sensors or the door's reversing mechanism. Look along the full width of the opening at floor level.
3The sensor wiring is damaged
Sensor wires run along the wall and up to the opener, often stapled in place. They get nicked by stored items, chewed by rodents, or pulled loose over time. If the lenses are clean and aligned but a sensor light still won't stay on, the wiring is the next suspect. This one is worth having a tech handle.
4The opener's close-limit setting has drifted
Your opener has a limit setting that tells it exactly how far to travel before the door is fully closed. If that setting drifts, the opener thinks the door has hit an obstruction and reverses. The tell: the door closes almost all the way, then goes back up.
The fix: most openers have adjustment screws or buttons for travel limits — your manual will show the location. Small adjustments only. If you overshoot, the door will press into the floor and strain the motor.
5The track is bent or obstructed
If the door binds, catches, or stops at the same point every time, look at the tracks. A dent from a bumper, a loose bracket, or debris in the channel will stop a door cold. Bent track is not a DIY repair — forcing a door through a damaged track will bend panels and can pull rollers out entirely. See our track and roller repair service.
6A broken spring is making the door too heavy
When a spring fails, the opener can't control the door's weight. Some doors won't close at all; others slam down and bounce back up. If you also heard a loud bang recently, or the door feels extremely heavy when lifted by hand, this is almost certainly it.
7The remote, wall button, or logic board has failed
If nothing happens at all — no motor hum, no movement — the problem may be electrical rather than mechanical. Try the wall button and the remote separately. If the wall button works but the remote doesn't, it's usually a battery or reprogramming issue. If neither works, the logic board or motor may have failed, which calls for opener repair.
Stop using the door
A door with a failed spring can drop without warning. This requires professional spring repair — springs hold enormous stored tension and are genuinely dangerous to work on without the right tools.
What you can safely try yourself
Cleaning and realigning the safety sensors, clearing obstructions, replacing remote batteries, and small limit adjustments are all reasonable homeowner fixes. That covers a real share of "won't close" calls.
What to leave to a technician
Anything involving springs, cables, bent track, or sensor wiring. Garage door springs carry enough tension to cause serious injury, and a door that's off balance can fall. If your door is stuck open and you can't secure your home, that's an emergency — we're available 24/7 for emergency repair.
One September note for Bay Area homeowners
Fall is when we see "won't close" calls spike. As the rains return, moisture collects on sensor lenses, leaves and debris pile along the bottom seal, and the temperature swings stiffen up hardware that was fine all summer. A ten-minute check now — wipe the sensors, clear the track, lubricate the rollers — prevents most of it.
If your door still won't close after the basics, call (669) 369-3795. We're based in San Jose, we run same-day service seven days a week, and our trucks carry the parts to finish most repairs on the first visit.