How to tell if your garage door spring is broken (and why not to DIY it)

The short answer

If you heard a loud bang from the garage and now the door won't go up, or only lifts a few inches and stops, you almost certainly have a broken garage door spring. That's the single most common call I get. Leave the door where it is, don't keep pressing the button, and call me at (619) 930-7869. I'll tell you what's wrong before I quote the price.

The springs do the heavy lifting on a garage door, not the opener. A typical two-car door weighs a lot more than people think, and the springs are wound or stretched to balance almost all of that weight. When one breaks, the opener suddenly has to lift the whole door by itself, and it usually can't. Everything below is about what to look for with your eyes and ears. None of it involves touching the spring.

Seven signs your spring is broken

• You heard a bang like a gunshotSprings release their tension in an instant. Most people describe it as a firecracker or a shot in the garage, often when nobody was using the door. Springs usually fail at rest, after the door has been sitting closed.
• There's a gap in the coil above the doorLook up at the bar above the door from the floor, with the door closed. A torsion spring that has snapped shows a clear gap of a couple of inches somewhere along the coil, or two separate pieces where there used to be one.
• The door goes up a few inches and stopsMost openers have a safety setting that stops them when the load is too heavy. The motor hums, the door lifts a little, and then the opener quits or reverses. That's the opener protecting itself.
• The door feels very heavyIf the opener is already disconnected and you try to lift the door, it feels like it's bolted to the floor. A balanced door should lift with one hand. Don't force it. If it won't come up easily, stop.
• The cables are slack or hangingThe lift cables run from the bottom corners of the door up to drums at the ends of the spring bar. When a spring breaks, the cable on that side often goes loose or jumps off its drum. A dangling cable is a stop-everything sign.
• The door is crookedOn doors with two springs, or with side-mounted extension springs, one side can lose its lift while the other keeps working. The door rises unevenly, or one corner sits higher than the other.
• An extension spring is hanging looseIf your springs run along the horizontal tracks on each side of the ceiling instead of above the door, a broken one looks stretched out, sagging, or hanging from its safety cable.

Why I tell people not to fix it themselves

I get it. The parts are sold online and there are plenty of videos. But spring work is the one garage door job where a small mistake turns into a trip to the emergency room. A torsion spring is wound with a set of steel bars, and if a bar slips out of the winding cone, the spring unwinds and the bar flies. Extension springs that break without a safety cable inside them can throw metal across the garage.

There's also the matching. The spring has to suit the weight and height of your door: wire size, inside diameter, length, and how many turns it gets. A spring that's close but not right leaves the door out of balance, which wears out the opener and the spring early, and the door can drop when it should stay put.

When I replace springs, I weigh and measure the door, fit the right springs, check the cables, drums and bearings while everything is apart, replace the safety cables on extension springs if they're damaged, and test the balance before I leave. On a two-spring door I'll usually recommend replacing both, because they've done the same number of cycles and the second one is rarely far behind.

What to do right now

If your car is stuck inside, don't try to squeeze it under a partly open door. Most spring jobs are done in one visit, so it's usually a short wait. If you want to know what goes into the price before you call, my spring repair cost guide explains it without the guesswork.

1. 1Stop using the openerRunning the opener against a broken spring can strip its gear or burn out the motor, and it can pull the door off track. Unplug it if you can reach the plug safely.
2. 2Leave the door where it isIf it's closed, leave it closed. If it's partly open, don't try to lift it the rest of the way or pull it down. A door with a broken spring can drop fast.
3. 3Keep people and pets clearNobody walks under the door, and kids stay out of the garage until it's fixed.
4. 4Take a photo if you canA picture of the spring area from the floor helps me bring the right parts on the first visit.
5. 5Call for a repairI offer same-day or next-day service, a free estimate and no trip fee. If you call and I miss it, you'll get a callback within the hour.

Can you stop a spring from breaking?

Not forever. Springs are rated for a certain number of open-and-close cycles, and every spring wears out eventually. You can stretch the life, though. Keep the door balanced, keep the rollers and hinges moving freely so the springs aren't fighting friction, and get a look at the springs once a year. Rust on the coils shortens their life, so a light coat of lube on a tune-up helps, especially near the coast.

If you want the numbers on lifespan, I wrote a separate guide on how long garage door springs last. And if you're in East County, I handle spring repair in La Mesa and the cities around it on the same schedule as Central San Diego.