The Inner Workings of the Garbage Disposer

By Dave Donovan

If appliances were movie stars, then the garbage disposer would be in the tabloids every week. It's been one of the more controversial appliances in recent history. It was actually banned in New York City until 1997. The ban was put in place because officials believed that the garbage being sent down the drain would have a damaging effect on the city's sewer system. As a matter of fact, in countries in Europe and in the U.K., it's still hard to find people who own one. They've also become known as one of the deadliest appliances in the house. That is, if you believe every horror movie you've ever seen. It never ends well when someone drops a ring down the drain. Despite the bad rap and bad-boy image, the garbage disposer is still one of our most used appliances in the kitchen today.

Many people associate the spinners inside the garbage disposer with the actual blades. That's incorrect. The spinners are actually dull and are used to push the food toward the outside edges of the disposer. That's where the shredders are. Here's how a garbage disposer really works.

Food items get stuffed into the disposer through the sink drain. Inside the disposer there are a series of spinners that spin freely - they're sometimes called "the hammers." The hammers are connected to a turntable that is spun around by the motor. Along the outer wall of the disposer are the shredders. When you turn the disposer on, the motor spins the turntable at an extremely high rate of speed. This causes centrifugal force that pulls the food outward toward the shredder. The hammers spin around and assist with pushing the food into the shredder. The shredder tears the food into tiny parts that get flushed down the drain along with the water. Garbage disposers should never be run without the water running. They are dependable appliances, but let's see if you've ever had this experience:

You just had a big dinner and instead of throwing the debris left on the dishes into the garbage, you choose to stuff it all down the drain. Make sure no silverware sneaks in! You hit the switch on the wall, the disposer screams to life and then... nothing. You flip the switch a couple of times only to be met with a humming and then a "click." Now when you hit the switch, you don't even get the humming.

This is a common problem and an easy one to fix. This is just one of the problems you may face with your garbage disposer. Ahead, we'll look at more, but first let's fix this one.

When a disposer gets jammed, there is a button underneath that trips out. It's best to wait about 15 minutes and then hit the reset button. It's located on the bottom of most disposers and it's usually colored red. If you push it in and you hear a "click," then it's been reset. With the water running, try turning the disposer on again. If it's really jammed, it will probably trip again. If it does, leave the switch off and don't hit the reset button yet. Remove any large items from the disposer with a pair of tongs - don't forget the scary movies! Next, grab a long screwdriver and try to get it to catch hold in one of the bottom holes on the turntable. Once it catches, try to manually turn the turntable to help break the jam. Once you free the obstruction, remove the screwdriver, hit the reset button, turn the water on, and hit the switch. It should be running smoothly now. Throw the big debris in the garbage can next time!

Now, let's look at a few other problems and their remedies.

Problem: The disposer isn't running at all.
Solution: It could be the problem we just went through, or it could be a power problem. Check the power to the circuit that feeds the disposer. If the breaker is OK, then check the power at the switch. If you have power coming to, but not leaving the switch, then the switch is bad. Turn the circuit off and replace the switch.

Problem: The disposer is draining poorly.
Solution: Make sure that the water is running full blast when using the disposer. The more water, the better drainage. If it's still draining slow, disconnect the "J" bend in the drain and check for a clog. Sometimes grease and other nasty things will accumulate in your pipes over time.

Problem: The disposer is leaking.
Solution: If it's leaking around the drain, try tightening the screws on the sink mounting ring. You will need an offset screwdriver to be able to reach the screws once the disposer is already assembled. If the leak is coming from the drainpipe, tighten the screw that holds the drain gasket. If the leak persists, try replacing the drain gasket.

Problem: The disposer is very noisy.
Solution: While it's not the quietest appliance in normal situations, it can become really noisy if something gets in there to cause a ruckus. With the switch off, grab a flashlight and take a look down the drain and see if you notice anything that can be causing the noise. Plastic or metal items are usually the culprits. Fish out the item with tongs. If there's nothing in the disposer, check the mounting screws. They could be loose enough that when it's turned on, it vibrates enough to cause a lot of noise. It could also mean that you have a damaged flywheel. If that's the case, you're better off buying a new disposer than going through the motions of trying to replace that.

All in all, the garbage disposer's not that bad a guy. He's dependable, he's there when you need him, and he doesn't complain about taking out the trash. With these simple repairs, your relationship with this bad-boy should last for years. If you don't have a garbage disposer yet or would like to install a new one, read our step-by-step installation guide here.

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