Garage door won’t open: causes and safe next steps

First: is the problem the door or the opener?

The opener is a motor that moves a balanced door. The springs do the heavy lifting. When a door will not open, the most useful first question is whether the door itself is mechanically stuck or heavy, or whether the opener is failing to act on a door that is otherwise fine.

You can usually tell from two observations: what the opener does when you press the wall button, and what the door looks like. A motor that runs while the door stays put points to one set of causes; a motor that does nothing points to another; a door that is visibly crooked or has a gap in a spring points to the door.

A broken spring

The classic signs are a loud bang from the garage, a visible gap of an inch or two in a torsion spring above the door, or an extension spring hanging loose beside the track. The door then feels extremely heavy, and the opener may lift it only a few inches, strain, and stop or reverse.

Do not try to lift the door or run the opener repeatedly. A door without its counterbalance can weigh well over a hundred pounds, and the remaining hardware is under stress. This is a spring replacement, and it is a job for a trained technician.

A cable problem

If one side of the door sits lower than the other, or a cable is visibly frayed, slack or wound off its drum, a lift cable has failed or displaced. The door may bind in the tracks and refuse to move. Cables work with the springs and are under the same tension, so leave them alone and keep people clear of the opening.

The door is off its track or obstructed

A door that hangs crooked, has rollers outside the track, or has a visibly bent track section has come off track, often after an impact or a cable problem. Forcing it can damage the sections. Also check for the simple obstruction: a tool, a bin or debris in the track can stop a door that is otherwise fine.

An opener or control fault

• Nothing happens at all. Check that the opener has power and that the wall control’s lock or vacation mode is not switched on, which disables remotes on many models. If the wall button works and the remote does not, the remote battery or programming is the likely issue.
• The motor runs but the door does not move. On some openers this points to a worn drive gear or a disengaged trolley. If the door was disconnected with the emergency release cord, it will move by hand but not by motor until it is re-engaged.
• The door starts, then stops or reverses. Travel and force settings, a binding door or a fault the opener is detecting can cause this. Opener indicator lights often flash a diagnostic pattern; the meaning is specific to the brand and model, so note the pattern for the technician rather than assuming a cause.
• The door opens by hand but is heavy. If the door is hard to lift manually with the opener disconnected, the problem is the door’s balance or hardware, not the opener.

What to tell the technician

1. What the opener does when you press the wall button, and separately the remote.
2. Whether you heard a bang, grinding or straining, and when it started.
3. Whether the door is level, crooked, partly open or fully closed, and whether a vehicle is trapped inside.
4. The opener brand and model if the label is safely visible, and any indicator light pattern.
5. Any recent event: a storm, an impact, a power outage or a prior repair.