Common Repairs for Garbage Disposals
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Common Repairs for Garbage Disposals

How to run and repair your garbage disposal.

Garbage disposals are one of the few household appliances that people either love or hate. Many people enjoy the convenience they offer with disposing of small food scraps. Others contend that they are troublesome and dangerous and can actually damage the sewer system. If you have a garbage disposal, this article will help solve some common problems associated with their operation.

Garbage Disposal Schematic

While it may sound like a wood chipper under your sink, a garbage disposal does not have cutting blades. The spinners are dull and are used to push the food toward the outside edges of the disposal towards the grinding ring.

Garbage Disposal Schematic

Operation and Repairs

Food items are placed in the disposal through the sink drain. Inside the disposal there are a series of spinners that spin freely on pivots, sometimes caller impellers. The impellers are connected to a flywheel that is connected to the motor and rotates at high speed. Along the outer wall of the disposal is the grinding ring. Most disposals are controlled by a standard light switch that energizes the motor. The food is forced to the outside grinding ring with the help of the impellers. The grinding ring shreds the food into tiny pieces that are flushed down the drain with the running water.

Problem: The disposal runs for a few seconds then shuts off or hums.

Solution: The motor has an overload protection switch in the unit that will trip when the motor overheats. This happens when large items or foreign objects prevent the flywheel from spinning. There is a button underneath that the unit that will pop out when the overload is tripped. You should wait about 15 minutes before resetting to allow the motor to cool down. It is typically on the bottom of the unit and is often red. When you press it you should hear a click. Turn on the water and then try the disposal again.

If it becomes jammed again and trips, shut off the unit and look inside the drain with a flashlight to see if there are large items stuck inside. Remove any large items from the disposal with a pair of tongs. With a long screwdriver try to insert it into a hole on the flywheel to see if it is free. Garbage disposals come with a wrench that can be inserted into the bottom if the unit to turn the shaft. Rotate the shaft back and forth a few times with the wrench to help grind up the jam. Reset the safety button and try the unit again.

Problem: The disposal isn't running.

Solution: If you tried the steps in the first problem, check the breaker for the circuit that feeds the disposal. If the breaker is on, then check the power at the switch. If you have power on the hot side of the switch, but not on the disposal side, the switch is bad. Turn the circuit off and replace the switch.

Reset Button and Electrical Connection

If you have power to the switch you may have a loose connection inside the wiring connection inside the unit. See where the wire enters the bottom of the disposal and there will be a small access cover that can be opened to access the wire connections. Open the cover and check the connections. If they are in good shape, turn the power back on and see if you have power to the wire connections. If you do, the overload may have failed or the motor could be bad. You will need to replace the unit.

Problem: The disposal is draining poorly.

Solution: Make sure that you have adequate water flow when using the disposal. If it's still draining slowly, disconnect the drain connection and check for a clog. Over time food debris can build up in the bottom of the trap and slow the drainage of the unit.

Problem: The disposal 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 disposal 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 garbage disposal is very noisy.

Solution: Garbage disposals are usually noisy, but if you should be able to notice a difference when there are scraps in the unit and when it is clear. If you hear a metallic clicking noise or a high pitched grinding noise, there may be plastic or metal items stuck under the impellers or in the grinding ring. Try to remove the item with tongs. If the disposal is clear, check the mounting screws. They could be loose and cause the unit to vibrate.

It may also have a damaged flywheel or one of the impellers can be stuck in one position. It is often easier to replace the unit instead of repairing it.


If you just need to clean your garbage disposal, put ice cubes and baking soda down the drain and turn the disposal on for about 10 seconds.

Grind a lemon while running warm water to deodorize your garbage disposal.

Always run cold water when grinding in order to move the waste all the way through the drain lines. Fats and grease congeal and harden in cold water which can then be flushed through the system. Don't use hot water when grinding because it can dissolve fats and grease, which may then accumulate in the drain line


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Comments (1)

Nicely done, Daniel. You must be psychic because I was thinking about doing an article on garbage disposal repair and you graphic looks looks almost identical to the one I was going to use. Happy holidays to you and yours.