If your garage door is opening slowly or making a lot of noise, the problem may not be your opener. So before you buy a new one, check for broken or wobbly rollers and brackets. But don't replace the bottom roller bracket yourself—the cable attached to it is under extreme tension. You'll need to call a pro. If you're replacing the rollers, get nylon rollers. They operate quieter than steel rollers and cost only a few bucks more. Next, check the torsion spring (mounted on the header above the door opening) to see if it's broken. When one breaks, you'll see a gap in the coils. You'll need a pro to replace a broken spring.
Read more on garage door opener repair and troubleshooting.
Make sure the door is balanced. Close the door and pull the emergency release cord (always close the door first so it can't come crashing down!). Lift the door about halfway up and let go. The door shouldn't move. If it slides up or down, the torsion spring needs to be adjusted (or maybe even replaced). Adjusting the torsion spring is dangerous, so don't attempt it yourself (you could get seriously hurt). Call a pro to adjust it.
When buying an opener, choose a 1/3 hp or 1/2 hp opener for a single garage door (1/3 hp can be hard to find at some home centers). Go with 1/2 hp for a double door and 3/4 hp for a door that has a wood or faux wood overlay (they can be heavy!). Openers have a set opening speed, so installing an opener with a higher horsepower won't open your door any faster.
Openers are available with a chain drive, screw drive or belt drive. Chain drives (a long chain pulls the door open and closed) are the least expensive, but they're loud. Screw drives (a long threaded rod drives a mechanism that opens and closes the door) are priced in the mid- range. They require the least maintenance, but they're not as quiet as belt drives. Belt drives (a rubber belt opens and closes the door) are the quietest, making them the best choice if you have living space above the garage. They're also the most expensive.
Follow the manufacturer's instructions to assemble the opener and mount the rail to the header bracket above the door. Then set the opener on a ladder where you're going to install it. The ladder (usually an 8-footer) holds the opener in position while you measure for your lengths of angle iron. If necessary, put boards under the opener to raise it.
Have the door open when you install the opener (clamp locking pliers onto the roller track below a roller to keep the door from closing). It's easier to align the opener with the center of the door when the door is open.
Garage door openers come with everything you need for installation. But the mounting straps that are included are often so flimsy that you can bend them with your hands. So buy slotted angle iron at a hardware store. Cut it to size with a hacksaw.
Angle iron provides a stronger installation and reduces vibration, which helps extend the opener's life span. In an unfinished garage, attach the angle iron directly to the face of a joist with 1-in. lag screws. For finished ceilings, attach angle iron along the bottom of a joist with 3-in. lag screws. Hang the opener using two more lengths of angle iron and nuts and bolts. Use lock washers or thread-locking adhesive to keep vibration from loosening the nuts.
Don't be tempted to reuse the old photoelectric eyes and wall button (opener button). The new photo eyes and wall button are designed to work with your new opener.
If the wires that run from your opener to the photo eyes and to the wall button are exposed, replace them, too. Those wires have probably been in your garage for 10 years or more, and they may be nicked or worn. Newer openers are extremely sensitive and won't work if a wire is damaged. It only takes about 15 minutes to run the new wire, so it's time well spent. If the wires are protected inside the wall, you don't need to run new wire.
Your instructions probably don't cover checking the opening force. If your door encounters more than about 5 lbs. of resistance when it's opening, you want it to stop. This is an important safety feature. The “resistance” could be your finger caught in the track.
To check the opening force, rest your foot on the door handle near the floor and open the door using the remote control. When the door lifts against your foot, it should stop with very little pressure. If the door continues to open, adjust the force.
The opener's instructions probably tell you to place a 2x4 on the floor under the center of the door, then close it. When the door contacts the wood, it should stop and then reverse. Proper closing force ensures that if something is in the door's path, the door won't crush it.
The locations of the opening and closing force adjustment screws vary. Our unit has two screws on the front. When adjusting the opening or closing force, turn the screw only about 1/8 in., then recheck the force.
If the door starts to open and then stops on its own, increase the opening force. Likewise, if it stops on its own while closing, increase the closing force. You might have to make several small adjustments to get the force exactly how it should be.
Garage door openers vibrate, so you'll need special light- bulbs that can handle it. Look for “rough service” or “garage door” on the label.
Be sure to use the wattage specified in your manual. If you use a higher wattage, the heat could melt the plastic cover over the bulbs or even damage the circuit board inside the opener.
This is one place where LED or CFL bulbs aren't the best choice. LEDs have a low light output, and CFLs aren't designed to handle the vibration. And since the lights are on only briefly, the energy saved with these bulbs would be negligible.
The most common problem with garage door openers is the door reversing when it's closing, even when there's nothing obvious obscuring the photoelectric eyes. If your closing force is adjusted correctly, then the problem is almost always the photoelectric eyes. The eyes are very sensitive— even cobwebs can interfere with them. First make sure the eyes are still in alignment (some- thing may have knocked them out of whack). Then make sure the eyes are clean and the path between them is clear. Finally, look for loose wires in the eyes and the opener.