Garage Door Won't Open? Run This 5-Minute Diagnostic Before You Call Anyone

A door that won't open has a short list of causes, and you can narrow it down in five minutes without tools. Work through these in order:

1. Look at the spring above the door. A healthy torsion spring is one continuous coil. If you see a two-inch gap in it, the spring is broken — that's the loud bang you may have heard. Stop here. Don't keep hitting the opener button (it will burn out lifting weight it can't handle) and don't lift the door by hand; a double-car door weighs 150–350 lbs without its counterbalance. This is a call-a-pro failure.

2. Check the emergency release. If the red cord was pulled (kids, moving boxes), the opener trolley is disconnected. With the door fully closed, pull the cord toward the door to re-engage, then run the opener.

3. Check power and lockout. Is the opener's light on? Check the outlet and breaker. If a wall-button light is flashing, the lock/vacation mode may be on — hold the lock button a few seconds.

4. Watch what the opener does. Hums but nothing moves: stripped drive gear or seized trolley. Runs and the belt/chain moves but the door doesn't: broken trolley or disconnected arm. Clicks once: often a capacitor or board.

5. Check the photo eyes. Two small sensors near the floor on each side. Both should have solid lights. Blocked, misaligned, or blinking: the door will often open but refuse to close — realign until both lights go solid.

The two never-DIY failures: a broken spring, and a door that's come off its tracks. Both leave the system storing or misdirecting hundreds of pounds of force, and both are the source of most garage door injuries. Everything else on this list is safe to check yourself.