Troubleshooting Garbage Disposal Problems

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  • 01 of 05

    Garbage Disposal Safety

    Male Hand Using Wrench on Kitchen Sink Garbage Disposal
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    The horror movie image of victims having hands and arms severed in a garbage disposal is entirely a Hollywood invention. In reality, the blades inside a garbage disposal are rather dull grinders, not gleaming, razor-sharp sabers. That is not to say that a disposal should be taken lightly—it is indeed possible to be painfully injured if you don't practice basic safety measures. 

    But there is really only one rule you need to follow: Never put your hand or fingers down into the disposal, even if you think the disposal has been unplugged or its circuit has been shut off. If a disposal gets turned on accidentally while your fingers are in the opening, the likelihood is that you will end up with bruised fingers, not bloody amputation. But this is not a risk that is necessary in any way.

    NEVER reach into a garbage disposal.

    If you follow that basic rule, the most common problems with a garbage disposal are easy to diagnose and almost always easy to fix. 

    Continue to 2 of 5 below.
  • 02 of 05

    Garbage Disposal Will Not Turn On

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    If the disposal will not turn on when you flip the switch and you do not hear the humming sound of the motor, it indicates there is an electrical problem that is preventing the appliance from getting current. To identify the problem and fix it, begin with the most likely problem (and easiest solution) and proceed to the more complicated:

    1. Make sure the disposal is plugged in. This may seem obvious, but appliance customer service representatives report that failure to plug in the appliance is by far the most common source of problems. 
    2. If it is plugged in, then press the reset button found on the bottom of the unit. This red button operates a built-in circuit breaker function, and if the reset button has "tripped," it will be popped slightly outward. Simply pushing it back in will reset the unit.
    3. If depressing the disposal reset button doesn't work, then check the main service panel to see if the circuit breaker has tripped. If so, reset the circuit breaker's lever. 
    4. If neither the reset button nor the circuit breaker is the cause, then it's possible that there is a wiring problem with the switch controlling the disposal, or that the garbage disposal itself is faulty.
    5. First, locate the switch that powers the disposal unit. It should be located on the wall, but it may be under the sink.
    6. At the main service panel, turn off the circuit breaker that powers the disposal circuit.
    7. Disassemble the switch controlling the disposal. Inspect the wire connections. In some cases, a simple loose connection may be the cause of the problem, and the remedy is as simple as tightening the wire connections. 
    8. If the wire connections are secure, it's possible the switch itself is bad. Replace the switch
    9. Turn power back on at the service panel and check the disposal for operation.
    10. If the disposal still does not turn on and the motor makes no noise, the garbage disposal is beyond repair and needs to be replaced.
    Continue to 3 of 5 below.
  • 03 of 05

    Disposal Hums But Does Not Grind

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    If the garbage disposal won't turn on but the motor makes a humming sound when you flip the switch, it indicates that the inner flywheel is jammed. Usually, this causes the appliance's reset button to pop or the circuit breaker to trip very quickly. This is not a situation you want to continue for very long, as it can burn out the disposer's motor unless the reset button or circuit breaker shuts things off. 

    The problem is almost always the result of food or a foreign object being lodged between the impeller(s) and the shredder ring inside the disposal. (Learn about the anatomy of a garbage disposal in order to better identify the various parts.)

    Reminder: Never put your hand down into the garbage disposal hopper (grinding chamber).

    1. Turn off power to the garbage disposal at the electrical service panel by shutting off the breaker controlling the circuit. Also, turn off the wall switch controlling the disposal.
    2. Take the offset wrench that came with the disposal unit and insert it into the flywheel turning hole in the bottom of the unit. If you don't have the wrench, you can pick one up from the hardware store that sells your garbage disposal. A large Allen (hex) wrench may also work.
    3. Once the wrench is inserted, turn it clockwise to dislodge the stuck impeller or flywheel. When it dislodges, you'll feel the flywheel turn freely.
    4. Another approach is to use a wooden spoon handle or similar wooden object to reach down into the disposal through the drain opening, using it as a lever to free the stuck flywheel. If you're successful, you'll feel the flywheel begin to turn freely. 
    5. Use a flashlight to look down into the disposal. If you see the object that caused the jam (wayward meat bones and pieces of dinnerware are common culprits), use pliers to remove the foreign object. 
    6. Once the flywheel is freed, turn the power back on at the main service panel but don't turn on the disposal yet.
    7. Go back to the disposal and press the red reset button on the bottom.
    8. Run some tap water into the disposal and quickly flip the switch on and off for a short burst. Turn on and off again quickly. This should spin the flywheel and cause any dislodged debris to be washed down the drain.
    Continue to 4 of 5 below.
  • 04 of 05

    Disposal Is Leaking

    Plumber using adjustable pliers on sink drain
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    Garbage disposal leaks can occur from a number of places on a garbage disposer. Common areas include the sink flange where the disposal connects to the bottom of the sink, the hose that leads from the dishwasher to the disposal, and hose that discharges waste from the disposal to the drain system.

    Leak at the Sink Flange

    The constant vibration of a garbage disposal, over time, can loosen the mounting apparatus that holds the appliance to the sink drain opening. This sink mounting flange is a likely place for leaking. 

    1. Turn off power to the disposal at the electrical service panel by shutting off the circuit breaker that controls it.
    2. At the disposer mounting ring under the sink, turn the disposal to the left (counter-clockwise from bottom) to loosen and remove the unit from its mounting flange.
    3. Tighten down the three mounting bolts holding the flange to the sink.
    4. If the bolts are tight, the leak may be caused by failed plumber's putty. Loosen the bolts and push the sink flange slightly above the surface of the sink.
    5. Force a bead of new plumbers putty between the sink flange and the sink, going completely around the flange.
    6. Re-tighten the mounting bolts from below, drawing the sink flange tight to the sink surface. When excess putty oozes out, wipe away the excess. 
    7. Reinstall the disposal and turn the power back on at the service panel.
    8. Check for leaks as you run the water in the sink.

    Leak at the Dishwasher Connection

    The rubber hose that funnels waste water from the dishwasher to the garbage disposal is also a place where leads frequently occur. 

    1. Tighten the hose clamp on the dishwasher hose connected to the dishwasher inlet on the disposer.
    2. Replace the hose if the hose continues to leak.

    Leak at the Discharge Drainpipe

    Another plastic pipe carries directs waste water from the disposal to the sink drain trap, and this fitting can leak when the gasket​ get old.

    1. Check the bolts holding the discharge pipe to the disposal, making sure they are tight.
    2. If this does not work, remove the bolts and the pipe and replace the gasket seal between the pipe and the disposal.
    3. Reinstall the bolts and tighten them down.
    Continue to 5 of 5 below.
  • 05 of 05

    Disposal Drains Slowly

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    Slow draining of a garbage disposal can be caused by a number of problems, but it's usually caused by the same kind of clogging that can slow any sink drain. Usually, the fix involves disassembling the drain trap and discharge pipe and removing any food waste clogging the pipes. 

    1. Remove the bolts holding the discharge pipe to the disposal.
    2. Disconnect the drain trap and remove the trap and the discharge drain pipe.
    3. Check for clogs or obstructions and clean out any you find.
    4. If none are found, the clog probably lies on the branch drain line going into the wall. Clear the obstruction with a ​sink auger
    5. Reassemble the drain trap and reconnect the discharge tube to the side of the garbage disposal. 
    6. Run water, turn on the garbage disposal, and check to make sure the water runs freely. 

    Warning: Never use chemical drain cleaners with a garbage disposal. These chemicals rarely work, leaving you with a sinkful of toxic chemicals. Further, such chemicals often damage the garbage disposal and void the manufacturer's warranty. 

    There are several good practices to remember (and some bad ones to avoid) that will reduce the chances of clogs or slow-draining problems with your garbage disposal. 

    Don't:

    • Grind up potato peelings. Peelings form a starchy paste similar to mashed potatoes when ground up, which will surely clog your drain.
    • Put coffee grounds or egg shells into your disposal. They create very tiny bits of granular waste that will stick to any sludge in the pipe and quickly create a clog.

    Do:

    • Maintain your disposal by regularly grinding up pieces of lemon peel and ice cubes.
    • Avoid odors by treating your disposal every month by mixing a couple of handfuls of baking soda with a half cup of vinegar. Pour the mixture into the disposal hopper with the unit turned off. After the mixture is done foaming, rinse it down the drain with running water.