Garage Door
Why you shouldn't touch a garage door torsion spring
A loud bang in the garage with nothing on the floor usually means the torsion spring above the door has snapped. Leave it alone. That spring, not the opener, carries the weight of the door, and resetting one takes winding bars and training. Stop pressing the opener button, don't pull the red release cord if the door is stuck open, and call a garage door company.
It's a quiet evening, and there's a bang from the garage loud enough to make you jump. You go look. Nothing fell off the shelves, the car is fine, and the door is closed. The most likely culprit is sitting right above the door: the torsion spring just broke.
What a torsion spring actually does
Most people assume the opener lifts the door. It doesn't. A typical residential door weighs a lot more than the small motor on your ceiling could handle on its own. The torsion spring, the tightly wound coil on the metal bar above the door, is what counterbalances that weight. The opener just guides the door up and down once the spring has made it feel light.
To do that job, the spring is wound with a huge amount of stored tension every time the door is closed. That's the whole problem. When a spring holding that much energy is disturbed by someone who doesn't know how to control it, it can spin a winding bar, a wrench or a loose part with enough force to break bones.
How to tell the spring broke
You don't need to climb anything to check. Stand on the floor and look up at the bar above the door.
| What you notice | What it usually means | What to do |
|---|---|---|
| A visible gap in the coil, often a couple of inches wide | The spring has snapped in two | Leave the door where it is and call for service |
| The door barely moves, or the opener strains and stops | The weight is no longer balanced | Stop pressing the button |
| The door goes up crooked or one side hangs low | A spring or a lift cable may have failed | Keep people and cars out of its path |
| A cable hanging loose beside the door | Cable came off its drum, often after a spring break | Don't pull on it or try to rewind it |
If you can't see the coil clearly, that's fine. A door that suddenly feels like it weighs a ton after a loud bang tells you most of what you need to know.
The rule: leave it alone
Safety first: Don't loosen, tighten, unbolt or "just check" anything on the spring, the bar above the door, the cable drums at each end, or the brackets at the bottom corners of the door. All of those parts are under tension. Resetting a torsion spring takes purpose-made winding bars and training, and people get badly hurt trying it from a video.
The bottom brackets deserve a special mention. They look like a simple bolted plate at the bottom corner of the door, and they're easy to reach. On many doors the lift cable anchors right there, which means those bolts can be holding back the spring's tension. Leave them alone too.
Three things not to do while you wait
- Don't keep hitting the opener. The motor isn't built to lift a door on its own. Pressing the button over and over can strip gears or burn out the motor, which turns a spring repair into a spring and opener repair.
- Don't pull the red release cord if the door is stuck open. That cord disconnects the door from the opener. With a broken spring, nothing is holding the door up once you pull it, and it can come down hard and fast.
- Don't try to prop it and drive out. A door that is partly open with no working spring can drop without warning. If your car is stuck inside, say so when you call. It helps the company decide how soon to send someone.
Keep kids and pets out of the garage until a tech has been out. If you need to get in and out of the house, use another door.
What happens on the service call
A trained tech will secure the door, unwind whatever tension is left, and install a spring sized to your door's weight and height. On two-spring doors they'll often suggest replacing both, because the one that didn't break has worked just as many cycles. They should also check the cables, drums and rollers, since a spring break can stress those parts.
Ask for the price before work starts, and ask what's included. If a company can't tell you what spring they're installing or how long it's rated for, that's worth a second call to another company.
The monthly 2x4 test
Springs aren't the only safety part on a garage door. The opener has an auto-reverse feature that should stop and back the door up if something is under it. Here's how to check it once a month:
- Clear the doorway. Move the car out and make sure nobody, including pets, is near the door.
- Lay a 2x4 flat on the floor in the middle of the door's path, so the wide side is down.
- Close the door with the opener. Stand clear and watch it come down.
- Watch what happens at the board. The door should touch the 2x4 and reverse back up right away.
- If it doesn't reverse, or it presses down on the board and stops, stop using the opener and call for service.
While you're at it, check the photo eyes, the two small sensors near the floor on each side of the door. Start closing the door and wave a broom handle through the beam. The door should stop and go back up. Your opener's manual may describe its own version of both tests, so follow that if it's different.
For garage door pros: sharing this with customers
Most spring calls start with a scared homeowner who has just tried the opener five times. A short safety note sent before that moment saves you a burned-out motor and saves them a lot more. A few ways owners share it:
- Link this page in your follow-up email after any tune-up, with a line like "Keep this in case you ever hear a bang."
- Show the customer the 2x4 test at the end of every visit. It takes a minute and they remember who taught them.
- Post it in late fall, when cold snaps tend to bring a wave of broken springs.
When those calls come in, the caller's first questions tell you how urgent the job is. A car trapped inside is a very different call from a door stuck halfway open. There's more on sorting those calls on the garage door page, and the numbers behind every unanswered one are in what a missed call costs.
Common questions
Can I still open my garage door by hand if the spring is broken?
Usually not safely. Without the spring, you'd be lifting the full weight of the door, which is far more than most people expect, and it can drop the moment you lose your grip. If a car is trapped inside, tell the garage door company when you call. Many companies treat a trapped vehicle as a same-day job.
Should both torsion springs be replaced if only one broke?
On doors with two springs, many techs recommend replacing both. They were installed together and have worked the same number of cycles, so the second one is often close behind. Ask the tech to explain their recommendation and give you both prices before any work starts.
Is a garage door extension spring any safer to work on than a torsion spring?
No. Extension springs stretch along the tracks on each side and store a lot of energy too. When one breaks without a safety cable running through it, parts can fly across the garage. Treat any broken or loose spring, cable or bottom bracket as a job for a trained tech.
How long does a garage door torsion spring last?
Springs are rated in open and close cycles rather than years, so a door that runs many times a day wears its spring out faster than one used twice a day. Rust and cold weather also shorten their life. A tech can tell you what's on your door and whether a longer-life spring makes sense.