I heard a loud bang in the garage and now the door won't open

Likely causes, most common first

A bang followed by a door that will not lift has only a few explanations, and a snapped torsion spring is far ahead of the rest.

1. Most common

   A torsion spring snapped

   The sign: A gap of about two inches has opened in one coil on the shaft above the door, and the opener could not raise the door after the bang.

   The fix: Replace the broken spring, or both springs on a two-spring door, wound to the weight of your door and balance tested before we leave. Garage Door Spring Replacement, from $249

2. Common

   An extension spring broke

   The sign: On an older door with long springs running beside the horizontal tracks, one spring is stretched out or in pieces, held by the safety cable through its center or lying on the floor if there was none.

   The fix: Replace both extension springs as a matched pair, and thread safety cables through them if the door never had any. Garage Door Spring Replacement, from $249

3. Common

   A lift cable snapped or jumped its drum

   The sign: Every coil on the shaft looks whole, but a cable hangs slack at one bottom corner and the door sits lower on that side.

   The fix: Replace both lift cables, check the drums for grooves and cracks, and square the door back in its tracks. Garage Door Cable and Drum Repair, from $189

4. Less common

   A roller popped out of the track

   The sign: The door jolted to a stop partway, at least one roller sits outside the track, and a section looks twisted or bowed.

   The fix: Secure the door, reset the rollers, straighten or replace the bent track, and correct whatever pushed the roller out. Off-Track Garage Door Repair, from $179

5. Less common

   The opener stripped its drive gear

   The sign: The noise came from the opener head rather than above the door, and now the motor runs or hums while the chain or belt sits still and the springs look intact.

   The fix: Replace the drive gear and sprocket, then check the door balance so the new gear is not doing the job the springs should be doing. Garage Door Opener Repair, from $149

What you can safely check in two minutes

You can narrow this down from the floor in a couple of minutes, without touching anything that holds tension.

• Look up at the shaft above the closed door. A clean gap of about two inches in one coil means a broken torsion spring.
• On an older door with springs along the side tracks, check whether one spring hangs loose, sags or lies on the floor.
• Look at both bottom corners for a cable that hangs slack or has come off its drum, without touching the cable or the bracket.
• Note whether the door sits level or lower on one side, then take one photo from the driveway and one of the spring.
• Unplug the opener so nobody presses the wall button or a car remote out of habit.

Why a spring breaks with a bang

The bang, often compared to a gunshot, is stored energy letting go all at once when a fatigue crack in the coil gives way. A torsion spring holds the energy that lifts your door, and every cycle brings the steel closer to failure.

Standard residential springs are commonly rated around 10,000 cycles, a typical figure rather than a promise. Rust in a damp garage, a door that was never balanced, or a spring sized too small for the door all shorten it, and a worn spring can give out on any trip, the first lift on a cold morning included.

Can I get the car out with a broken spring?

Not by lifting it. With a spring broken, the door stays where it is, because nothing is carrying its weight and a door that slips from tired hands comes down hard on whatever is under it.

If a car is trapped inside, say so when you call and we move the schedule; until we arrive, leave the red release cord alone and keep the opener unplugged. A closed door with a dead spring is safest sitting still.

What else can break when a spring lets go

A spring break can take the cables with it and, if the opener kept running, the top section and the opener gear too.

The lift cables go slack the instant the spring stops holding tension, and they can slip off their drums. An opener that ran after the break may have bent the top section where its arm attaches, or worn down its own gear.

We check all of that on the visit, because a new spring on a door with a frayed cable or a cracked top section just moves the next failure a few weeks down the road. Anything worn gets shown to you and priced before it is replaced.

When to stop and call right away

Call promptly and keep everyone clear of the door if any of these apply.

• A cable is hanging loose or a bottom bracket looks pulled away from the door.
• The door is stuck partway open and will not stay where it is.
• Pieces of an extension spring came loose and no safety cable was inside it.
• A car is trapped in the garage and has to get out today.
• Someone has already tried loosening a winding cone or a bottom bracket.

Related pages

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