Home Doctor

Doors & Windows guide

Garage door won't close: sensors, springs and what's safe to fix

By the Home Doctor team · Reviewed

Quick answer

A garage door that starts down and then reverses, or won't close at all, most often has a safety sensor problem: the two small photo eyes near the floor on each side of the door are dirty, blocked or out of line. Clean the lenses, clear the path and adjust them until both lights glow steadily. Also check for a lock button on the wall control and a dead remote battery. A loud bang, a gap in the spring above the door or a loose cable means a broken spring or cable. Don't touch those: a technician typically charges $150 to $600 to replace the springs.

How urgent
Urgent

A door stuck open leaves the garage, and often the house, unsecured, so deal with it within a day. Most causes are a quick sensor fix. It becomes 'stop and call a pro now' if a spring or cable is broken, or the door is off its track or hanging crooked.

DIY or pro
DIY if handy

Cleaning and aligning the sensors, clearing the path, and checking the lock and remote battery are simple DIY. Adjusting the close limit is a handy job with the opener manual. Springs, cables, tracks and bottom rollers are for a garage door technician.

Stop and call a pro now if

  • A loud bang, a visible gap in the spring above the door, or a loose or snapped cable: don't run the opener or lift the door. Springs and cables store enough energy to cause serious injury. Never adjust, loosen or replace them yourself: call a garage door technician.
  • A spring or cable is broken and the door is open: don't pull the emergency release. Without the spring holding it, the door can drop hard. Keep people, pets and cars out from under it.
  • The door is off its track, hanging crooked or jammed partway: leave it alone and keep everyone clear. It can fall. Call a technician.
  • The door doesn't reverse when it hits a 2x4 on the floor or when you block the sensor beam: stop using the opener until it's fixed. It can seriously injure a child or pet.

Common causes and how to tell them apart

  1. 1. Dirty, blocked or misaligned safety sensors

    How to tell
    The door goes down a little, then reverses, and the opener's light may blink. One of the small lights on the sensors near the floor is off or flickering, a sensor has been bumped out of line, or low sun shines straight into one.
    What fixes it
    Wipe the lenses, clear anything in the beam, and adjust the brackets until both sensor lights glow steadily. Check the thin sensor wires for cuts, loose staples or chew marks.

  2. 2. Something in the door's path

    How to tell
    The door stops and reverses at the same spot every time. A bin, a tool, snow or debris is under the door, or something is caught in one of the tracks.
    What fixes it
    Clear the floor under the door and look along both tracks for anything stuck in them.

  3. 3. Close limit or force set wrong

    How to tell
    The door reaches the floor, then goes right back up, and the sensor lights stay steady. It often starts after a new opener or bottom seal, or in cold weather when the door moves more stiffly.
    What fixes it
    Adjust the close limit on the motor unit (a screw, dial or buttons, depending on the model) so the door just seals against the floor. Follow the opener manual. Don't just turn up the close force: that weakens the safety reversal. Repeat the 2x4 test after any change.

  4. 4. Lock button on or remote battery dead

    How to tell
    The wall button works but the remote or keypad doesn't, and a lock light may be on at the wall control. If nothing works at all, the opener may have lost power.
    What fixes it
    Turn the lock feature off (on many wall controls you hold the lock button for a few seconds) and replace the remote's battery. If nothing works, check that the opener is plugged in and the breaker or garage GFCI outlet hasn't tripped.

  5. 5. Broken torsion or extension spring

    How to tell
    A loud bang like a gunshot, then the door is very heavy and the opener strains or stops after a few inches. A torsion spring on the bar above the door has a gap in its coils. An extension spring along either overhead track hangs loose or looks stretched.
    What fixes it
    A garage door technician replaces the springs, usually both at once. Don't run the opener or lift the door in the meantime.

  6. 6. Snapped or loose cable, or rollers off the track

    How to tell
    The door hangs crooked with one side lower than the other, a cable is slack or dangling near a bottom corner, rollers have come out of the track, or the track is bent. Often after a car bumps the door or a spring breaks.
    What fixes it
    A technician resets the door, replaces the cable and straightens or replaces the track. Leave the door where it is until then.

Not sure which one you have?

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What you can safely try first

  1. 1Look for danger signs first: a gap in the spring above the door, a loose cable or a crooked door. If you see any of them, stop here and call a technician.
  2. 2Clear the floor under the door and check both tracks for anything in the way.
  3. 3Wipe the lenses of both safety sensors with a soft cloth, and adjust the brackets until both small lights glow steadily.
  4. 4Check the wall control for a lock light and turn the lock off, then replace the remote battery.
  5. 5To close it now, press and hold the wall button until the door is fully down: many openers override the sensors this way. Watch it the whole time and keep people, pets and cars clear. If that fails and the springs and cables look intact, close it by hand with the red emergency release cord.
  6. 6Once it closes normally, lay a 2x4 flat on the floor where the door lands and close the door. It should reverse as soon as it touches the board. Repeat this test every month.

When to call a pro

  • Any sign of a broken spring or a loose or snapped cable.
  • The door is crooked, off its track, or the track is bent.
  • The door still reverses with the sensors aligned and the path clear, or it fails the 2x4 test.
  • The opener hums, grinds or runs without moving the door.

What it costs

Typical costs to fix: garage door won't close
JobDIY partsPro, installed
Garage door service call—$75–$200
Replace a pair of safety sensors$30–$90$100–$250
Replace springs (pair, torsion or extension)Not recommended$150–$600
Replace lift cablesNot recommended$150–$350
Put the door back on track or replace rollersNot recommended$150–$450
Replace the opener$180–$500$400–$1,000

Ballpark US ranges as of September 28, 2026. Your region, access and the specifics of your home can move these a lot. Get two or three quotes for anything over a few hundred dollars.

What to tell the pro

My [single / double] garage door [starts down, then reverses / won't move at all / hangs crooked]. The opener light [blinks / doesn't blink], and the sensor lights are [both steady / one off or flickering]. I [heard a loud bang / didn't hear anything unusual], the spring above the door [has a gap / looks intact], and the cables [look fine / are loose or hanging]. The door is about [age] years old. If it's the springs, will you replace both, and does your price include new cables, a roller check and a safety test of the opener?

Questions people ask

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

Usually the safety sensors. If they're dirty, bumped out of line, blocked or hit by direct sun, the opener thinks something is in the way and reverses. Clean the lenses and adjust them until both lights glow steadily. If the sensors are fine and the door reverses right after touching the floor, the close limit likely needs adjusting.

How do I close my garage door manually?

Only if the springs and cables are intact: no gap in the spring above the door, no loose cable, and the door hangs level. Pull the red emergency release cord, then lower the door slowly by its handle, keeping fingers out of the joints between panels. Many openers reconnect on the next run, and if you slide the side lock closed, unlock it before using the opener again.

How much does it cost to fix a broken garage door spring?

Typically $150 to $600, depending on whether it's a torsion or extension system and whether both springs are replaced, which most technicians recommend. It isn't a DIY job: the springs store enough energy to cause serious injury. Don't open the door or run the opener until it's fixed.

How do I test my garage door's auto-reverse?

Lay a 2x4 flat on the floor in the middle of the door's path and close the door. It should reverse as soon as it touches the board. Then close it again and pass something like a broom handle through the sensor beam: it should reverse. If it fails either test, stop using the opener until it's fixed, and repeat the test every month.

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General guidance, not a substitute for a licensed professional who can see the problem in person. If you smell gas, see sparks or smoke, or anyone is hurt, leave the area and call 911.