Broken garage door spring: how to tell, and what not to touch

What are the signs of a broken garage door spring?

Most people notice one or more of these:

• A bang from the garage, like a gunshot or something heavy falling, often with nobody near the door. Amarr notes that a broken torsion spring may make a loud bang while the pieces stay on the bar (Amarr).
• A gap in the coil. Look at the spring above the door. A whole spring is one continuous coil; a broken one has a visible space, as if a section had been cut out.
• A door that suddenly weighs far more. A balanced door lifts easily by hand. With a broken spring it can feel like dead weight.
• The opener strains, lifts a few inches, then stops or reverses, or the motor runs and the door barely moves.
• A crooked door, higher on one side, or cables hanging loose from the bottom corners.
• The door drops fast when closing instead of settling gently.

You don't need all of them. A gap in the coil alone is enough.

Do I have torsion or extension springs?

Look above and beside the door.

Both are dangerous when they fail. A broken extension spring without a safety cable running through it can whip loose, and Amarr warns that parts can fly around the garage.

Why shouldn't I run the opener or lift the door?

Because the springs, not the motor, lift the door. The opener is designed to guide a door that the springs have balanced. With a spring gone, the opener is trying to haul the full weight of the door, and that can strip its gears, bend the door's top panel or snap a cable.

Lifting by hand is risky for the same reason. Chamberlain warns that if the springs are weak or broken, the door may fall rapidly and without warning (Chamberlain). Garage doors are heavy, and a dropping door can crush hands, feet, a pet or a car hood.

And never try to repair or adjust the spring. Garaga, a Canadian door maker, says plainly that torsion springs can be very dangerous (Garaga), and the winding is done with special bars and procedures for a reason. The cables and bottom brackets are under the same tension.

If your car is trapped inside and you're thinking about the manual release, read how to use the garage door manual release first; the first step there is checking for exactly this.

"It broke on one side but still works." Is that safe?

No. On a door with two torsion springs, the remaining one is now carrying the whole load. The door is out of balance, the opener is straining, and the second spring, which has done exactly the same number of cycles as the first, is under far more stress than it was built for. It can fail at any time, and when it does, there's nothing holding the door at all.

Treat a door with one broken spring as a door with a broken spring: stop using it and book the repair.

Why do springs seem to break in the cold?

Springs wear out with use. Each open-and-close cycle flexes the steel, and eventually it fatigues and cracks. Cold doesn't create that wear, but it often finishes the job: a spring near the end of its life, working a door that's stiffer from cold grease and a frozen seal, is more likely to let go on a minus thirty morning. Garaga notes that springs can be affected by rust and cold weather.

The door industry's own technical guidance adds that rust reduces the strength of spring wire and that doors in climates with extreme cold should be kept closed where possible (DASMA TDS-190). A garage door left open on cold days, or a damp garage where springs rust, shortens their life.

How long springs typically last, and how to work out where yours are, is in how long do garage door springs last.

What does a spring replacement involve?

A proper spring job is more than swapping a coil:

• Matching the spring to the door. The right spring depends on the door's weight, height and drum size. A heavier insulated door needs a stronger spring.
• Considering both springs on a two-spring door, since they've done the same work.
• Checking the cables, drums and bottom brackets, which take a shock when a spring breaks.
• Balancing the door so it stays put halfway up by hand.
• Testing the opener's safety reverse once the door is back in balance.

Garage doors are a 24/7 service. If you've found a gap in the coil, leave the door where it is, keep people and cars clear of it, and book garage door spring repair.

If it's winter and the springs look fine but the door still won't move, the cause is probably something else; see garage door won't open in cold weather.