Garage door won't close? Here's how to fix it.

Why won't my garage door close?

A garage door that won't close is usually the safety sensors — the two small eyes near the floor that stop the door if anything crosses their beam — followed, less often, by a track, spring, opener-setting, or remote problem.

We check the sensors first because they are far and away the most likely culprit. Every residential opener built since 1993 is required by federal safety rules to have a second, independent way of noticing something in the doorway — almost always a pair of photo-eyes, occasionally a sensor strip along the bottom edge of the door. That means nearly every door in Sacramento has an invisible beam across the opening whose entire job is to refuse to close. And it sits a few inches off a dirty garage floor, where a broom, a bike tire, or a stray box can knock it out of line. Most likely to be disturbed, most likely to be the problem — so it's the first thing to check.

When the door opens fine but refuses to close, that one-directional behavior is the giveaway — the opener is deliberately declining to lower a door it thinks has something underneath it.

Here's the short ranked list of what causes it, most common first. Each links to its section below:

• Blocked, misaligned, or dirty safety sensors — by far the most common.
• An opener down-force or travel-limit setting that's off, so the door reverses before it seals.
• A broken spring or cable — the door is too heavy to move (call a pro).
• Opener, remote, or power problems — dead battery, logic glitch, lost program.
• A bent track, bad roller, or debris physically blocking the door.

Why your garage door won't close: symptoms and causes

Match what your door is doing on the left, and start with the fix on the right. If two rows fit the symptoms, work down the list — sensors first.

Start with the safety sensors — the #1 cause

To fix sensor problems, make sure nothing is breaking the beam, wipe both lenses clean, and adjust the brackets until both indicator lights glow steady. A flickering or dark light means the beam is broken — that's what stops the door from closing.

The two safety sensors (also called photo-eyes) mount to the tracks, one on each side. Manufacturer standards are to install the beam no higher than 6 inches above the garage floor. One side sends an invisible infrared beam, the other receives it.

What happens when that beam breaks depends on when it breaks. If it's already broken when you press the button, the door won't start down at all. If it breaks partway through a close, the opener reverses the door back up. Either way the opener is doing its job, not failing.

How to know it's the sensors

Three quick tells, no tools needed:

• Check the lights. Each sensor has a small LED. On LiftMaster and Chamberlain units, amber is the sending eye and green is the receiving eye; Genie's Safe-T-Beam pair uses red for the source and green for the receiver. Whatever the colors, both should be steady.
• Try the hold-button test. If the door closes only while you hold the wall button down (more on that below), the opener is closing with the sensors out of the loop — which means the sensors are the issue.
• Look for an obvious block. Crouch to floor level and sight across the beam path. A bin, a hose, even tall debris along the bottom seal can break it.

How to clean and realign the sensors

Here are the steps:

1. Clear the floor near the door.
2. Wipe both lenses.
3. Loosen the wing nut on the receiving sensor.
4. Point the two lenses directly at each other.
5. Tighten the wing nut once that light glows steady.
6. Confirm both LEDs are solid.
7. Finally, test the door with the remote or wall control.

A dedicated step-by-step alignment guide — light colors, the string-leveling trick, why sensors keep drifting, and how to tell when one has actually failed — is in the works and will be linked here when it publishes.

When realigning isn't enough

Most of the time that routine is the whole fix — nudge the receiving eye until the light goes steady, snug the wing nut, and the door closes. But it doesn't work every time. If the light won't go steady at all, or it holds for a day and then drifts back out, the sensor usually isn't the real problem — something underneath it is moving. A loose mounting bracket. A track section that has worked its fasteners loose. A sensor wire that's pinched, corroded, or broken inside its insulation. Or simply a door shaking hard enough on every cycle to walk the eye back out of line. Adjusting the eye doesn't fix any of that; it just resets the clock until it drifts again.

So here's our honest advice. Run the alignment, tighten anything obviously loose while you're down there, and give the door a few cycles to see whether it holds. If it does, you're done — and that's the common outcome. If it doesn't, then you may have a more complex problem to solve.

If you're handy and want to keep chasing it yourself, the possible causes and things to check include the sensor bracket, the track fasteners near it, the wire run end to end including up at the opener terminals, and whether the door is visibly shaking the sensor as it moves. We run these calls every day, so if you'd rather hand it off than work through the list, that's exactly what we're here for.

Garage door closes then reopens

If the door starts down and bounces back up before it seals, start with a misaligned sensor. If the sensors are clean and aligned and the opener isn't flashing a sensor code, it's usually the down (close) force or the down travel limit — the opener is reading normal resistance as an obstruction.

Work through it in this order:

• Sensors first. A beam that's intermittently broken — a sensor on the edge of alignment, or a dirty lens — makes the door reverse partway down. Run the sensor checks above before anything else.
• Then the door itself. Anything that makes the door bind — a dry roller, a track pulled off the wall, an out-of-balance door — raises the resistance the opener feels and trips the same reversal. Disconnect the opener and move the door by hand: it should glide, and stay put where you leave it.
• Down force. The force setting tells the opener how much resistance the door should present, and it reverses if it feels more than that. Chamberlain's guidance for a door that reverses during the close cycle while the opener lights are not flashing is to increase the down force in small steps until the door completes a close.
• Down travel limit. This is the separate setting that tells the opener where the floor is. Set too far, the door reaches the floor and the opener keeps pushing, so it reverses; the fix is to decrease down travel. Older units adjust with screws on the motor head, newer ones with buttons or up/down arrows — check the label on the housing for which you have.
• A small obstruction at the threshold. A pebble or a worn bottom seal catching on the floor can stop the door just short and trip the reverse.

If the sensors are clean, the door moves freely by hand, and the settings look right but it still reverses, the opener's logic board may be the problem — that's the point to call.

It only closes when I hold the button down

If the door closes only while you hold the wall button, the opener is closing with the photo-eyes out of the loop. That's a deliberate, manufacturer-documented override — Chamberlain's own troubleshooting says the door "can be closed by pressing and holding the Door Control push bar until down travel is completed" while you work out the sensor problem. The fact that it works only that way is the diagnosis.

By design, the opener won't power a door closed on its own if the sensors say the beam is broken. But it will let a person stand at the wall control and hold the button, on the logic that whoever is holding it can see the doorway. So this is a diagnosis, not a fix: go clean and realign the sensors and normal one-tap closing comes back.

The sensor light is blinking — what it means

A flickering or dark sensor light means the safety-sensor beam is broken — misalignment, an obstruction, a dirty lens, or a wiring fault. A flashing light on the opener is more ambiguous, and it's worth knowing which of two very different things you're looking at.

On most systems the sending and receiving sensors each have a small indicator. Steady on both means the beam is intact. When the receiving side flickers or goes dark it has lost sight of the beam — go back to the cleaning and realignment steps.

On LiftMaster and Chamberlain openers the motor head reports the sensor circuit too: when the sensors are obstructed, misaligned, disconnected, or have a broken wire, the door won't close and the opener lights flash (or click) 10 times. Worth knowing before you count: Chamberlain notes that any opener or replacement logic board manufactured after February 3, 2022 no longer has that 10-flash feature, so a newer unit can be reporting a sensor fault silently. On Genie units, a flashing red Safe-T-Beam LED means the beam system has faulted — clean the lenses and check for obstructions, loose wires, and alignment.

Brand-specific resets (LiftMaster, Chamberlain, Genie)

Most brand-specific "won't close" issues still trace back to the sensors, but each brand has its own sensor-LED colors and reset routine. The fix is the same idea everywhere: restore the beam, then power-cycle if needed.

LMS services all the major brands — LiftMaster, Chamberlain, Genie, Craftsman, and myQ-equipped units. Here's the general approach for each; for exact LED colors and button sequences, check the label inside your motor housing or the manual, since they differ by model year.

If the lights are steady and a power-cycle didn't help, the opener may have lost its program or have a failing board — a quick service visit sorts out which.

The door is heavy or won't budge — is it a broken spring?

If the door feels extremely heavy, drops fast, or the opener hums but can't move it, you likely have a broken spring or cable — and that's a repair to leave to a pro, because the springs are under extreme tension.

The springs, not the opener, do the heavy lifting on a garage door. When one breaks you'll often hear a loud bang, find the door stuck or crooked, or see a clear gap in the coiled spring above the door. The opener is only built to guide a balanced door, not to hoist one: with the spring gone, the full weight of the door lands on a motor that was never sized for it, and it will strain, hum, and can burn itself out trying. A double door is commonly 150–250 lbs, more if it's insulated or solid wood, and with the spring gone all of that lands on you if you try to lift it.

Worth knowing why the "hum but no movement" symptom lands here: Chamberlain lists seven separate causes for it on a chain or belt drive — broken springs, the door lock being engaged, the trolley stuck on the stop bolt or stop tab, the door disconnected from the opener, a capacitor fault, motor damage, and a failed logic board. A broken spring is only one of them, and the two you can check yourself in a minute are the door lock and whether the trolley is still connected.

This is its own topic, with the tell-tale signs and honest pricing laid out separately. If the door is heavy, read how to tell if your spring is broken next — and stop using the door until it's looked at.

Opener, remote, and power problems

If the sensors check out and the door is balanced, the issue is usually an opener setting, a dead remote battery, or a power glitch — and unplugging the opener for about 30 seconds clears a surprising number of these.

• Power-cycle the opener. Unplug it, wait 30 seconds, plug it back in. This clears some logic and timing glitches — the garage-door equivalent of restarting a router. It will not clear a real sensor fault, and it won't cost you your settings: Chamberlain notes travel limits and forces aren't lost even when an opener sits unplugged for a long stretch.
• Remote vs. wall button. If the wall button closes the door but the remote won't, it's the remote — usually a dead battery or a lost program, not the door. If neither works, look at power and sensors.
• Force and travel settings. Openers have force and travel adjustments that can drift over time, causing the door to stop short or reverse. They're adjustable, but move in small steps — over-setting the down force weakens the obstruction detection that's meant to stop the door on contact. And run the reversal test with a 1½-inch object under the door afterward, every time. If the door won't reverse after repeated adjustment, stop and call for service.

Our opener repair page covers what we replace versus repair when a power-cycle and a fresh battery don't bring it back.

Tracks, rollers, and obstructions

A bent track, a damaged roller, or debris in the door's path can physically stop it from sealing. Inspect the tracks for dents and clear the floor along the bottom seal before assuming it's electronic.

This is lower on the list because it's less common than sensors, but it's easy to check:

• Sight down the tracks. Look for dents, bends, or spots where the track has pulled away from the wall. A flattened section will catch a roller and stall the door.
• Check the rollers. A cracked or seized roller drags instead of rolling. You'll often hear it — a grind or thunk at the same spot every time.
• Clear the threshold. Debris, a warped bottom seal, or built-up dirt where the door meets the floor can stop it from closing the last inch.

How to close the door manually (and re-engage it)

Read the warnings first: the manufacturers ask you to use the emergency release only when the door is fully closed, if possible, and never to pull the release handle in order to raise or lower the door. A door held up by a weak or broken spring can fall rapidly and without warning the moment you disconnect it.

One scenario people do run into: the motor runs, the chain or belt moves, and the door doesn't. That's the trolley disconnected from the opener — usually because the release cord got pulled at some point. It looks like a dead opener and it's a two-minute fix. (Note that a disconnected trolley stops the door moving in both directions, so if your door opens normally and only refuses to close, this isn't it — go back to the sensors.)

• To disconnect: with the doorway clear, pull the red release handle. The door is now free of the opener and moves by hand.
• To lower it: with hands on the door, not the cord, bring it down slowly and evenly. Only with a balanced door — if a spring is broken, don't lower it by hand at all (see above).
• To reconnect: this varies by rail. On a T-rail, pull the cord straight down and then run the opener — it reconnects on the next cycle. On a square rail, pull the cord toward the opener until the arm sits horizontal again, then run a full open/close cycle. On a wall-mount unit, pull the handle down firmly until it clicks, then run the opener.

A full manual-operation walk-through, including power-outage cases, is in our separate guide to opening a garage door by hand.

When to stop and call a pro

Call a professional if the door feels heavy or drops fast (spring or cable), the track is visibly bent, or the sensors are clean and aligned but it still won't close. Those point to mechanical or electrical faults that need the right tools and experience.

That being said, most "won't close" problems really are a five-minute sensor fix, and we'd rather you save the service call and do it yourself. But there's a clear point where DIY stops being safe or worthwhile — broken springs, bent hardware, a door off its track, or a fault you've chased without luck. That's what we're here for.

We're family-owned in Citrus Heights and have been repairing doors across the Sacramento area since 2018. No commissioned salespeople — actual technicians — and a written quote before any work starts. Our standard service call is $139: first hour of labor plus diagnosis, typically credited toward the repair when we do the work. If it turns out to be a sensor realignment, that's often all it is. You can see our repair services or send us your info and we'll take a look.

Frequently asked questions