White garage door on a suburban home in afternoon light, garage door wont close fix

How to Fix a Garage Door That Won't Close (Sensor + Alignment Fixes)

A garage door that won't close has 5 common causes, and 9 times out of 10 it's the safety sensors. Sensor realignment, lens cleaning, track adjustment, and when to call a pro.

By Chris Mendenhall

9 min read

Quick answer: A garage door that won’t close almost always means the safety sensors (the small electric eyes mounted near the floor on each side) aren’t seeing each other. Check the LEDs on both sensors; both should be solid, not blinking. Realign them by loosening the wing nut and tilting until both lights go steady. Wipe the lenses with a soft cloth, clear any cobwebs or stored items blocking the beam, and the door will close. If sensors check out, the next causes are misaligned tracks, a worn-out opener logic board, or a broken spring (call a pro for that last one).

A garage door that refuses to close has been a daily annoyance in millions of homes since safety sensors became code in the early 1990s. Those same sensors are also the easiest fix. Nine out of ten service calls for this problem are a five-minute visit where the tech wipes a sensor lens and collects $150. You can do that yourself in less time.

This walkthrough covers the five most common causes of a garage door that won’t close, from “free fix in 30 seconds” to “stop and call a pro before someone gets hurt.” Work down the list. Stop when you find yours.

What You’ll Need

  • A flashlight or your phone’s flashlight
  • A soft cloth (microfiber is best)
  • A 7/16-inch wrench or adjustable wrench (for sensor brackets)
  • A stepladder (for inspecting the track and opener)
  • A can of garage-door-specific silicone lubricant (not WD-40, see below)
  • Optional: a multimeter if you suspect a wiring issue

Step 1: Watch What the Door Actually Does When You Press the Button

The behavior tells you the cause. Stand in the garage and press the wall button (not the remote, the wall button rules out the remote being the issue). One of these will happen:

  • Door starts to close, then reverses back up: the safety sensors aren’t seeing each other (most common, see Cause 1).
  • Door starts to close, hits something, then reverses: the track has an obstruction or the sensitivity setting on the opener is too high (Cause 2).
  • Opener motor runs but door doesn’t move: the trolley has disconnected from the chain or belt, or the gear inside the motor is stripped (Cause 3).
  • Nothing happens at all: power, the opener logic board, or a wiring problem (Cause 4).
  • Door binds, makes a loud bang, or only partially closes: broken spring or off-track door (Cause 5, stop and read the safety note before doing anything else).

Cause 1: Safety Sensors Misaligned or Dirty

Federal law has required garage doors to have safety sensors since 1993. Two small plastic boxes mount near the floor on either side of the door opening, about 6 inches up. One sends an infrared beam, the other receives it. If the beam is broken (by a kid, a pet, a box) or the sensors aren’t pointed at each other, the door refuses to close as a safety feature. This is the cause 9 times out of 10.

Diagnose: Look at the LED on each sensor. (For the full sensor-by-sensor LED chart and wiring diagnostic, see our garage door sensors that won’t let it close guide.)

  • Both LEDs solid: sensors are working, problem is elsewhere.
  • One LED blinking, the other solid (or off): misalignment. The blinking one is the receiver, and it’s not seeing the beam.
  • Both LEDs off: power problem to the sensors (Cause 4).

Fix the alignment:

  1. Check first for the simple stuff. Any cobwebs across the lens? A cardboard box or bike leaning into the beam path? A stored cat? Move it.
  2. Wipe both lenses with a soft dry cloth. Sun fade, dust, and small spider webs across the lens are surprisingly common.
  3. If the LED is still blinking after cleaning, loosen the wing nut behind the sensor that’s blinking. The sensor will swing slightly.
  4. With the door open, tilt the sensor up and down (and side to side) until both LEDs go solid. You’ll feel it click into the right position.
  5. Tighten the wing nut without moving the sensor.

A common gotcha: sun glare. On bright afternoons, direct sunlight hitting a sensor lens can blind it and read as a broken beam. The fix is a small piece of cardboard or a sensor sun shield clipped above the offending sensor. Or wait until the sun moves and the door will close again.

Cause 2: Track Obstruction or Sensitivity Too High

If the door starts to close, then reverses on its own, the opener is detecting resistance somewhere in the track and treating it as something the door hit. The auto-reverse feature is mandatory by code, and it can be triggered by a worn roller, a slightly bent track, or a sensitivity setting that’s too tight.

Diagnose:

  1. With the door open, look up and along both tracks. Cobwebs and small debris are common.
  2. Run your hand along the inside edge of each track. Any dents, kinks, or bowed sections will catch a roller and trigger the reverse.
  3. Look at each roller. Worn, cracked, or rusty rollers don’t roll smoothly. Lifespan on plastic rollers is 8-10 years; nylon ball-bearing rollers run 15-20.

Fix:

  1. Clean any debris out of the track with a stiff brush or rag.
  2. Lubricate the rollers and hinges with garage-door silicone lubricant. Spray each roller as the door operates so the lubricant gets into the bearing. Skip the actual track itself, lubricant on the flat track surface just collects dirt.
  3. If a track is dented or bowed, you can sometimes tap it back into shape with a rubber mallet (door open, no tension on the system). Significant track damage means replacement, which is doable but it’s a job.
  4. If the door is mechanically fine but still reverses, the opener’s force/sensitivity setting is too tight. There’s a small adjustment screw or dial on the back of the opener motor labeled “down force” or “close force.” Turn it slightly clockwise (less than a quarter turn at a time) to slightly reduce sensitivity. Test after each adjustment. Don’t go too far, the auto-reverse is what stops the door from crushing a kid.

Why not WD-40: WD-40 is a solvent and a light lubricant. It evaporates within weeks and attracts dust. Garage doors want a silicone-based or lithium-based lubricant specifically formulated for the job, sold by Liquid Wrench, 3-IN-ONE, and DAP. Spray once or twice a year.

Cause 3: Disconnected Trolley or Stripped Gear

If you press the button and the motor runs but the door doesn’t move at all, the connection between the opener motor and the door has failed. Two common causes:

  • The emergency release cord was pulled. That red cord hanging from the trolley disconnects the door from the opener so you can move it by hand. To re-engage, pull the door fully closed by hand, then pull the cord toward the door (instead of toward the motor) to re-latch it. Or run the opener and it will automatically re-engage at the next position the trolley passes.
  • The opener’s drive gear is stripped. Older chain-drive openers have a plastic main gear inside the motor housing that wears out and strips around year 12-15. You’ll hear the motor running but no chain movement. Replacement gears are about $20 and an hour of work, or a whole new opener is $200-400.

Cause 4: Power or Logic Board

If the opener doesn’t react at all when you press the button, work through this:

  1. Try the wall button (not the remote). If the wall button works but the remote doesn’t, replace the remote battery (most use a CR2032, $2 at any drugstore).
  2. Check that the opener is plugged in. The outlet on the ceiling sometimes works loose. Make sure the GFCI hasn’t tripped (see how to reset a GFCI outlet).
  3. If still nothing, the opener’s circuit board may have failed. Lightning strikes are the most common killer. Board replacements run $50-150 for the part, plus your time.

Cause 5: Broken Spring or Off-Track Door (STOP, Call a Pro)

If the door is sagging on one side, won’t move at all even with the emergency release pulled, or you hear a loud bang when trying to operate it, a torsion spring has likely broken. Modern garage doors are heavy (150-400 pounds), and the springs above the door are under enormous tension. They store roughly 250-300 pounds of force when wound. A broken or improperly handled spring can cause severe injury or death.

This is the one part of garage door repair where you should not DIY. Pro replacement is $200-400. Pay it. If you see:

  • The door tilted at an angle
  • A visible gap in the spring (broken)
  • The door extremely heavy when lifted by hand
  • A loud bang followed by the door being inoperable

…stop, leave the door alone, and call a garage door service. The Consumer Product Safety Commission tracks dozens of deaths per year from torsion spring DIY accidents. (For the related situation where the door dropped off the track entirely, our garage door off the track diagnostic covers what’s still safely DIY and what isn’t.)

Common Mistakes to Avoid

Spraying WD-40 on the tracks. Not the right product. It washes off and collects dust. Silicone or lithium garage-door lubricant is what works.

Ignoring a slowly worsening problem. A door that’s started to reverse “sometimes” has a real cause, the rollers are wearing, the springs are weakening, or the sensors are drifting. Fix it now while the parts are cheap.

Disconnecting the safety sensors. Some people bypass the sensors to “make it work.” This is dangerous and illegal in most jurisdictions. The auto-reverse safety has saved kids’ lives since 1993.

Adjusting the opener force settings dramatically. Small movements only, a quarter turn at most. The default sensitivity is set for a reason.

Trying to fix torsion springs yourself. People die from this every year. Pay the pro.

Frequently Asked Questions

My garage door closes fine with the remote but not the wall button. Reverse of the usual problem. The wall button itself is failing, or the wire from the wall button to the opener has come loose. Wall button replacements are about $20.

The door closes most of the time, but sometimes reverses for no reason. Sun on the sensors at certain times of day is the most common cause. Watch the door at different times to see if there’s a pattern. A sensor sun shield ($10 at a home center) fixes it.

How often should I lubricate the garage door? Twice a year, spring and fall, with garage-door silicone or lithium spray. Hinges, rollers, springs, and the chain (if chain-drive). Skip the track surface.

My garage door is making a grinding noise but still works. Is that serious? Usually it’s worn rollers or a dry chain. Lubricate everything first. If the grinding is at the motor housing, the drive gear may be wearing, which is normal at the 12-15 year mark. Plan a replacement.

Can I install garage door sensors myself? If you’re replacing existing sensors (same brand and model), yes, swap them in 20 minutes. If you’re adding sensors to a pre-1993 opener that didn’t have them, the opener itself doesn’t support them and the whole opener has to be replaced.

A garage door that won’t close is usually trying to tell you the sensors aren’t seeing each other. Check the LEDs, wipe the lenses, clear the beam path, and you’ve solved the problem most homeowners pay $150 to have a tech do. Save the pro call for the broken springs and the dead logic boards, the things that actually need a pro’s tools and experience.

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