How do I know if my garage door spring is broken?

That's the short answer. The signs are easy to spot once you know what to look for, and knowing them helps you avoid forcing a door that can hurt you or damage the opener.

Signs your garage door spring is broken

Springs do the heavy lifting, so when one fails the symptoms show up right away. Watch for these:

• A loud bang from the garage. A torsion spring under tension snaps with a sound like a firecracker or a gunshot, often heard from inside the house. That bang is the most common first clue.
• A 2 to 4 inch gap in the spring. Look at the spring on the bar above the door. A broken torsion spring pulls apart and leaves a clear gap where the coils separated.
• The door won't open, or only rises a few inches. Without the spring, the opener can't lift the full weight. It may move the door six inches and stop.
• The door slams down. If you lift it by hand and it crashes back to the floor instead of staying put, the spring isn't holding the weight anymore.
• The opener strains, then stops. The motor hums or runs, the door barely moves, and the opener gives up. Forcing it again can burn out the motor.
• The door hangs crooked. One side lifts and the other drags, leaving the door tilted in the opening. That points to a broken spring or a snapped cable.
• Frayed or loose cables. When a spring lets go, the cables can come off the drums and hang loose along the sides of the door.

If you spot even one of these, stop using the door. The next sections explain why.

What a broken torsion spring does to the rest of the door

The spring carries almost all of your door's weight. The opener is built to guide a balanced door, not to haul a 150 pound slab on its own. Once the spring breaks, every other part starts taking a load it was never meant to handle.

Run the opener against a broken spring and you risk stripping its gears or burning out the motor, which turns a spring repair into a spring plus opener repair. The cables can jump the drums, the door can rack out of square, and a panel can bend. What starts as one broken part can cascade into several if you keep hitting the button.

This is also why a broken garage door spring counts as a same-day fix for most homeowners. The longer the door sits half-open or jammed, the more exposed your home is, and the more likely the damage spreads.

Why you should never fix a broken spring yourself

A garage door spring stores a huge amount of energy, even after it breaks. Winding or unwinding a torsion spring takes proper winding bars and exact technique, and a slip can break fingers, a wrist, or worse. This is the one garage door repair we tell homeowners to leave alone.

Here's where the honest line is:

• Safe to do yourself: confirming the spring is broken (the bang, the gap, the door that won't lift), unplugging the opener so nobody runs it, and parking your car outside until it's fixed.
• Pro territory: replacing or winding the spring, swapping cables, and rebalancing the door. These need the right tools and carry real injury risk.

If the door is stuck part-way and you need the car out, our guide on safely using the garage door emergency release and manual operation is the safer path than wrestling the door. Even then, a door with a broken spring is heavy and unpredictable, so go slow and keep hands and feet clear.

When to call a pro, and what comes next

Call a technician as soon as you confirm a broken spring. Our techs carry the common torsion spring sizes on the truck, so most spring jobs along the Front Range are done same-day. We measure the spring to your door's weight, replace it, check the cables and bearings, and rebalance the door so the opener isn't fighting it.

Two things homeowners usually ask once the spring breaks:

• How long should the new spring last? A standard spring is rated around 10,000 cycles, which lands near 7-10 years for an average household. Cold Denver winters and heavy daily use shorten that. Our breakdown of how long garage door springs last walks through what wears them out faster.
• What will it cost? Most torsion spring jobs run about $200 to $500 with parts and labor. See the full garage door spring replacement cost breakdown for what moves the price.

If you've got a double door and one spring broke, ask about replacing both. The second spring is the same age and the same number of cycles from failing, so doing the pair now usually saves a second service call within a year.