Garage Door Won't Close? What to Check First

Most doors that won't close have a blocked or misaligned safety sensor. Here's how to check it, and when to stop and get help.

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A garage door that won't close usually has a blocked, dirty or misaligned safety sensor, so the opener reverses the door as a precaution. Check the sensors first, then the lock button, the track and the springs.

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If the door is crooked, a cable is hanging loose or you heard a loud bang, skip the checks below and send a request with the form.

What the door does tells you where to look

Watch the door through one close attempt, and look at the opener's lights. The pattern narrows things down fast.

What happens	Most likely cause	Go to
Door starts down, then reverses within a foot or two; opener lights flash	Safety sensor beam blocked, dirty or out of line	Step 1
Door refuses to close only at a certain time of day	Sunlight shining into a sensor	Step 2
Remote does nothing, but the wall button works	Lock mode on, or a remote problem	Step 3 and remote troubleshooting
Door touches the floor, then goes back up	Close limit or force setting, or something under the door	Step 3
Door stops partway, feels heavy, or rides up crooked	Spring, cable or track problem	Step 4
Door closes only while you hold the wall button	Sensor fault on an older opener	Step 1
Nothing happens and the opener light is off	Power: outlet, breaker or GFCI	Check power first

Step 1: Check the safety sensors

Every opener sold in the U.S. since 1993 must have a second safety-reversing feature, usually a pair of photo-eye sensors, according to DASMA, the door industry's trade association. DASMA also says the eyes should sit no higher than six inches above the floor, so a child or pet can't slip under the beam.

Chamberlain Group, the parent company of the Chamberlain and LiftMaster opener brands, says the main lights flash 10 times when the opener sees a sensor problem. Its alignment steps:

Find the two sensors, one on each side of the door near the floor, usually fastened to the tracks.
Loosen the wing nut and point the lenses straight at each other.
When the sensor light glows steadily instead of blinking, tighten the wing nut.
Close the door with the remote or wall control to test.

Dust is the usual culprit here. When the Weather Service tracked the June 2019 haboob across the South Plains, the Lubbock airport logged a 47 mph gust and quarter-mile visibility. A thin film of that dust on a lens is enough to break the beam. Wipe both lenses with a soft cloth after windy days, and clear any leaves or trash blown into the beam's path.

Check the wires, too. Chamberlain's diagnostic chart ties one flash of the learn-button light to a broken or disconnected sensor wire, two flashes to a short or reversed wire, and four flashes to a misaligned sensor. Look along the wires for a staple driven through them or a spot a mower or bike has nicked.

Step 2: Rule out sunlight

Chamberlain says sunlight shining into the receiving sensor (the one with the green light) can block the infrared beam from the sending sensor (amber light). The opener then acts as if something is in the way. The giveaway is timing: the door closes fine most of the day, then refuses when the low morning or evening sun hits the opening. Shading the receiving sensor is a quick test. If it works, ask the company about a lasting fix, such as moving or swapping the sensors.

Step 3: Lock mode, travel limits and force

Lock mode. Many wall controls have a lock button. Chamberlain says that when lock is on, the opener still works from the wall control but the remotes are locked out, and the lights flash twice. Press lock again to turn it off.

Door hits the floor and reverses. The opener's close limit (how far it travels) or its force setting may be off, or something on the floor is in the way. Your manual explains both settings. DASMA warns that if a door doesn't reverse readily when it meets an obstruction, the sensitivity may be set wrong, which is dangerous, and it recommends a trained technician make the adjustment.

Step 4: Look at the door itself

LiftMaster's own list of reasons an opener isn't working includes a door that needs lubrication, a track out of line, a blocked path and broken springs. Those last three are door problems, not opener problems.

Look up at the springs with the door closed if you can. A gap in a torsion spring above the door, or a loose extension spring along the track, means a broken spring. See garage door spring repair.
Look at the rollers and track. Rollers out of the track, a bent track section or a dented section that catches as it rolls are reasons to stop. See off-track and cable repair.
Notice the effort. DASMA's checklist says safe operation of the door, opener and reversing system "is dependent on a balanced door." A door that feels heavy or struggles is out of balance. DASMA says spring systems "should be repaired only by trained professionals."

Don't touch springs, cables or the bottom brackets. DASMA says those brackets are under extreme tension.

If the door is stuck open

A door stuck open is a security problem and, during a storm, a wind problem. A National Weather Service survey estimated 80 mph winds from a downburst in northwest Lubbock in November 2015, and an open door catches wind like a sail.

Keep people, pets and cars out from under the door.
Stop pressing the button. Repeated tries can strain the opener or pull a binding door further out of line.
If the door looks straight and the springs are intact, work through the steps above. On an older Chamberlain or LiftMaster opener, holding the wall control down may close it.
If a spring is broken, a cable is slack or the door is crooked, leave it open and send a request with the form. Don't pull the emergency release on an open door with a broken spring.

What the fix usually costs

National guides checked in October 2026:

Fix	Typical national range	Source
Clean or realign sensors yourself	No cost
Replace a pair of sensors	About $70 to $190; $160 average	Angi
Professional sensor repair	About $150 to $250	Angi
Two springs on one door	About $150 to $350	HomeAdvisor

Angi notes that sensor replacement labor runs about $40 to $110 an hour and usually takes no more than an hour. Pricing and scheduling come from the company. For other parts, see the garage door repair cost guide.

If the opener itself is the problem, see garage door opener repair. If the door won't open at all, start with off-track and cable repair. Back to garage door repair in Lubbock for springs, openers, hail damage and new doors.

Common questions

Why does my garage door go back up when I try to close it?

Usually because the safety sensors near the floor think something is in the way. A dirty lens, a sensor knocked out of line, a loose wire or sunlight shining into the receiving sensor can all do it. If the sensors check out and the door still reverses near the floor, the opener's force or travel settings or a binding door may be the cause, and DASMA recommends a trained technician make those adjustments.

Why will my garage door only close if I hold the wall button down?

That's a sign of a safety sensor problem. Chamberlain says that on its older openers you can close the door by holding the door control until the door reaches the floor, but openers and replacement logic boards made after February 3, 2022 no longer have that feature. Treat it as a stopgap and fix the sensors.

How much does it cost to fix garage door sensors?

Angi puts sensor replacement at about $70 to $190, with a national average of $160 (updated October 2026), and a separate Angi repair guide puts professional sensor repair at about $150 to $250. Many sensor problems cost nothing: the lenses just need cleaning or realigning.

Can sunlight stop a garage door from closing?

Yes. Chamberlain's support pages say sunlight shining into the receiving sensor can block the infrared beam from the sending sensor, so the opener acts as if something is in the way. If your door only refuses to close at a certain time of day, suspect the sun.

My garage door is stuck open. Can I close it by hand?

Only if the door looks straight, the springs aren't broken and nothing is hanging loose. If a spring is broken, a cable is slack or the door is crooked, leave it open, keep everyone out from under it and get help. A door with a broken spring can drop hard if you release it from the opener.

Sources (11)

Last updated 2026-10-24