Garage door won't open or close?

A garage door that won't open, or won't stay closed, is the most common reason people call. The good news is that a handful of causes cover almost every case, and a few of them you can check yourself in five minutes. The rest involve parts under a lot of tension, so they're a job for a pro.

Start with what the opener does when you press the button

The sound the opener makes, or doesn't make, tells you a lot.

• Nothing at all, no light, no sound. The opener has no power or no signal. Check that it's plugged in, try the outlet with a lamp, and look for a tripped GFCI outlet or breaker. Then try the wall button instead of the remote.
• The motor hums or clicks but the door doesn't move. This is the classic sign of a broken spring. The opener isn't built to lift the full weight of the door. It can also mean the door is frozen to the floor or the drive gear inside the opener is stripped.
• The door lifts a few inches and stops or reverses. The opener feels too much resistance. Common causes are a broken spring, a frozen seal, a bent track or a roller that's binding.
• The light comes on and the motor runs, but the door doesn't move. The trolley may be disconnected from the door. Someone may have pulled the red manual release cord. With the door fully closed, you can usually reconnect it by running the opener until the trolley clicks back in.

When the door won't close

A door that starts down and then goes back up is almost always a safety sensor problem. The two small sensors sit about six inches off the floor on each side of the opening. If anything breaks the beam between them, or if one of them gets bumped, the opener reverses as a safety feature.

1. Clear anything from the doorway, including leaves, snow, recycling bins and spider webs.
2. Wipe both lenses with a soft cloth.
3. Check the indicator lights. On most brands one light is steady and the other blinks or goes out when the sensors are misaligned.
4. Gently adjust the bracket until both lights are steady.

This happens a lot on Waterbury's hilly lots, where garage floors often slope toward the street and the sensor brackets get knocked by shovels and snow blowers. If the sensors check out and the door still reverses, the close force or travel limit on the opener may need adjusting, which a technician can do in a few minutes.

Winter problems that look like a broken door

Waterbury averages about 23 nights at or below freezing every January, and close to that in December and February. That cold creates its own set of problems.

A frozen bottom seal. Snow melts off your car, runs under the door and refreezes overnight. The rubber seal is now glued to the slab. If you keep pressing the button, the opener can strip its gears or pull the door out of square. Instead, free the seal by warming it with a hair dryer or gently working a plastic scraper along the edge. Once it's free, spread a little sand or calcium chloride on the slab, not rock salt, which eats concrete and metal.

Stiff grease. Old grease in the tracks and on the rollers thickens in the cold and makes the door drag. Garage door tracks shouldn't be greased at all. A silicone or lithium spray on the rollers, hinges and springs is what most technicians use.

A spring that finally gives out. Springs are rated for a set number of open-and-close cycles. Cold steel is less forgiving, so a spring near the end of its life often breaks on a cold morning. If that's what happened, see our spring repair page.

If your car is stuck inside

This is the call people make most often on a weekday morning. If the door won't open and your car is in the garage, don't try to force the door up by hand or with the opener, and don't try to drive the car out under a door that's only partly open. With a broken spring the door can come down hard the moment you let go. Tell the company on the phone that the car is trapped. A technician can usually release the door safely or swap the spring so you can get out.

How long the fix usually takes

• Sensor cleaning or realignment: often a few minutes, and something you can usually do yourself.
• Opener adjustment, remote or keypad reprogramming: usually well under an hour.
• Broken spring: commonly one to three hours on site, depending on the door and whether one or two springs are replaced.
• Cable back on its drum, or a roller back in the track: often an hour or two, a bit longer if a track section has to be replaced.
• New opener: commonly a few hours, including programming remotes and testing the safety reverse.

What to tell the company when you call

• Exactly what the door does when you press the button: nothing, hums, lifts a few inches, or reverses.
• Whether you heard a bang, and whether you can see a gap in the spring above the door.
• Whether the door is stuck open or closed, and whether a car is trapped inside.
• The opener brand on the motor, and roughly how old the door and opener are.
• Whether the garage is attached or detached, and if the ceiling is low. That helps the technician bring the right parts.

Renting? Check with your landlord first

More than half of Waterbury's homes are rented, and a lot of them are two- and three-family houses with a shared or assigned garage. If you rent, look at your lease or call your landlord or property manager before booking a repair, since the owner is often the one who arranges and pays for it. Landlords with several doors across a few properties can ask the company to look at all of them on one visit.

When to call

Call a garage door company if the spring is broken, a cable is loose or frayed, the door is crooked, the opener hums without moving after you've ruled out ice, or the door simply won't respond after the checks above. Those parts are under hundreds of pounds of tension, and a mistake can cause a serious injury.

Common questions