My garage door opener hums but the door won't open. What's wrong?

You press the button, the opener hums or clicks, the light may come on, and the door does not move. Sometimes it shudders an inch and stops. Sometimes nothing moves at all.

The hum is good news in one way. It means the opener has power and heard the command. Something between the motor and the door is stopping it, and there are only a few places that something can be.

Stop pressing the button first. Every press runs the motor against a load it cannot move. That heats the motor, can strip the drive gear, and if a spring is broken, the opener is trying to lift the whole weight of the door by itself.

This guide covers home and business garage doors only.

Look at the springs before anything else

The most common reason an opener hums and the door stays put is a broken spring. The opener is built to guide a balanced door, not to lift one. With a spring gone, the door is far too heavy for it.

Look up from inside the garage, without touching anything. On most doors there is a spring on a metal bar above the top of the door. A broken one shows a clear gap in the coil, a few inches wide. On older doors the springs run along the tracks on each side, above the door; a broken one hangs loose or is missing.

If you heard a loud bang from the garage recently, it was very likely a spring.

If a spring is broken, stop here. Unplug the opener, leave the door where it is, and do not try to lift it by hand or with the opener. Spring, cable, and drum work is pro-only. The parts hold enough tension to cause serious injury.

Then watch the trolley for ten seconds

If the springs look whole, press the button once and watch the trolley. That is the carriage on the rail on the ceiling, with the arm that connects down to the top of the door. What it does tells you where the problem is.

• The motor hums and the trolley does not move at all, and the chain or belt sits still. The problem is inside the opener. A stripped drive gear, a worn sprocket, or a failed start capacitor are the usual causes. All of those are inside the motor housing, which is pro-only.
• The trolley runs along the rail, but the door stays where it is. The door is disconnected from the opener. Someone pulled the red emergency release cord, or the trolley did not re-catch after a power outage. This is the one you can usually fix yourself.
• The trolley starts to move, the chain or belt goes tight, and the door strains or lifts a little and stops. Something is holding the door. It may be the manual lock, a door frozen to the floor, a cable off its drum, a door binding in a bent track, or a spring the quick look missed.

What you can safely check yourself

• Unplug the opener before you touch the trolley, the rail, or the door.
• Check the manual lock. Many doors have a slide bolt or a handle lock on the inside of the door that pins it to the track. If it is engaged, the opener cannot lift the door. Slide it open.
• Check for ice in cold weather. A door can freeze to the floor along the bottom seal overnight. Free it gently with warm, not boiling, water or a plastic scraper, and clear the slush from under the door.
• Reconnect a disconnected trolley, with the door fully closed only. Pull the release cord toward the motor, or plug the opener back in and run it once. Most trolleys catch the door with a click.
• Look along both tracks and at the cables at the bottom corners. A cable hanging loose or off its drum, a roller out of the track, or a door hanging crooked means stop and call a pro.
• Find the model number on the opener's label. Write it down, along with roughly how old the opener is. It helps the technician bring the right parts.

What not to do

• Do not keep pressing the button to see if it works this time. That is how a gear problem becomes a burnt-out motor.
• Do not turn up the opener's force setting to push through it. The force setting is part of the safety system, and a door that needs more force has a door problem.
• Do not pull the emergency release while the door is open or partly open. If a spring is weak or broken, the door can drop.
• Do not lift a door by hand that has a broken spring or a loose cable.
• Do not touch the springs, cables, or drums, and do not open the opener's motor housing or anything behind an electrical cover plate. Those are pro-only.

Repair the opener, or replace it?

If the problem is inside the opener, the question is usually a gear and sprocket repair or a capacitor, against a new opener. On a younger opener with parts still made for it, the repair is usually the sensible choice. On an opener fifteen or more years old, or one that is also loud, slow, or unreliable, a new unit can make more sense.

The door comes first either way. If the door was hard to move, a new opener on the same door will wear out early too.

How it gets fixed, and what moves the price

A garage door technician starts with the door: the springs, the cables, the balance, the rollers, and the tracks. Then they check the opener's drive, the gear, and the capacitor, and set the force and travel limits once the door moves freely.

What moves the price is which part failed, whether it is a reconnection, an opener repair, spring or cable work, or a new opener, the size and weight of the door, and whether parts for that opener are still made. A reconnection or an adjustment sits at the small end. Spring work or a new opener is more. You see a qualitative range up front, and the technician confirms the price in person after seeing the door.

Booking through Roger

Describe what you saw: whether the trolley moved, whether a spring shows a gap, whether you heard a bang, whether the door is open, closed, or stuck partway, and roughly how old the opener is. Roger books one vetted local garage door technician and confirms the appointment, so you know which company is coming. Home and business only.

You can describe the problem on rogerrepair.com and get one garage door pro booked.