What to Do When the Garbage Disposal Won’t Drain

What is This Garbage?

Garbage disposal units to grind kitchen  foodstuff have existed for the last century. It’s a modern convenience which, like all modern conveniences, including your indoor plumbing, is something we don’t think much about until it stops working. Then it’s not very convenient.

A good example is when, all of a sudden, your garbage disposal in the kitchen sink will not drain. Or there is a slow drain and the sink is filled with water and food particles. Pretty disgusting, right?

Normally, you might take the standard steps to unclog a drain. But a clogged garbage disposal that doesn’t drain is, as someone once said in The Wizard of Oz movie,  a horse of a different color. As wizards of plumbing, we here at Benjamin Franklin Plumbing in the Bay Area can guide you through the process of how best to unclog a garbage disposal that won’t drain. Let’s take a look at what to do if:

    • You turn on the disposal and there is no sound
    • The disposal is spinning but not adequately draining
    • The disposal is not spinning, but there is a humming sound

First though, let’s take a look at how a garbage disposal works, and then next emphasize a primary rule about your garbage disposal that you must always follow.

ow a Garbage Disposal Works

You might think of a garbage disposal as a sort of blender of food waste, which is close, but not quite accurate. Here is how a garbage disposal actually works:

Food waste goes into a hopper, which has an upper and lower part. The waste collects first in the upper chamber of the hopper, and then slowly moves down into the lower chamber where the motor uses a combination of a flywheel and shredder ring and impeller blades to gring the food waste.

The flywheel is a rotating turntable connected to the shredder ring. Spinning impeller blades grind the foodstuff and force them back up into the shredder ring and flywheel assembly for further mincing and disposal.

Sufficiently crushed food waste falls through the shredder into the garbage disposal waste line and is then flushed down into the drain pipe and eventually out into the sewer system.

The Prime Directive

On Star Trek, the Prime Directive prohibits the crew from interfering in the natural progression of an alien civilization’s development. For any mission regarding your garbage disposal, the prime directive is: Do not interfere with the operation of your garbage disposal with your finger or hand

What if the disposal is off? The Prime Directive prohibits this. Even if you think the disposal is shut off or the circuit breaker is turned off. Because even if it is “off,” if something somehow makes it go back on, you do not want a finger or hand when the disposal begins to grind. You can imagine why this would be an unfortunate situation for your hand or finger.

Disposal is On, But There’s No Sound

    • If you turn on the disposal and there is no sound, check the circuit breaker for the kitchen to see if it has tripped. If it hasn’t, locate and press the red reset button on the bottom of the disposal unit under your sink. 
    • If this does not restore the system, call Ben Franklin Plumbing and one of our technicians will evaluate the disposal and discuss repair or replace options with you.

Disposal is Spinning, But Not Draining

Disposals can clog because food waste builds up and coats the waste line. One cause of this is not putting an adequate quantity of water down the disposal while it is processing the food waste. The water is needed to keep this relatively thick solution of water and food moving through the line and out into the main waste line to the sewer. 

Quick Tip #1: One good way to avoid clogs that cause a garbage disposal not to drain is to always, always run water down the disposal while it is grinding waste. Without sufficient water, waste is not completely flushed through the pipes and collects there.

Quick Tip #2: Even with sufficient flushing water, certain substances can easily clog. These include eggshells, celery, coffee grounds, animal bones, potato peels and banana peels. If at all possible, keep these out of the garbage disposal, however convenient it might be to put them there. Instead, collect them for use as compost or, if that’s not possible, put them in the garbage.  Also, it’s a good idea to avoid pouring grease down any drain whether you have a garbage disposal or not. Instead, collect grease in a pot or can and either bury the contents outside or put in your regular garbage.

If the disposal is spinning but not adequately draining, you can try to clean out the waste lines where a clog may have developed. Follow these steps:

    1. Fill the drain with ice cubes or uncooked pasta.
    2. Turn the water faucet on and turn on the disposal. 
    3. Wait for the grinding to stop.
    4. Check to see if the drain has returned to normal operation. 

If the answer to the last step is “yes,” then great, problem solved. If the answer is “no,” then not so great, you’ve got a real problem. In all probability, you have a considerable clog somewhere in the plumbing line. What makes the problem worse is that there are any number of places where the clog might be—in the drain line, the trap or any of the various joints in the drain line.

Here’s where you need an experienced plumber. A Benjamin Franklin plumber can quickly disassemble the several lines and locate the exact clog. If it is more than a clog or if the clog caused damage to the disposal unit, our professional can provide you with your best options for repair.

Disposal is Not Spinning, But Motor is Humming


If the disposal is not spinning but you can hear a humming from the motor, follow the steps below:

    1. Turn the disposal off.
    2. Look under the sink at the disposal motor. There should be an Allen wrench attached on one of the sides. (The installer should have left it there.)  
    3. Insert the Allen wrench into the fitting at the bottom of the disposal.
    4. Turn the Allen wrench clockwise. This should free up whatever might be jamming the motor. 
    5. Turn the disposal back on and test if it is spinning again.
    6. Put the Allen wrench back where you found it in case you ever need to use it again.

What if you don’t have an Allen wrench? An alternative is to insert a wooden stick spoon down through the sink drain into the disposal. Important: Do not insert anything into the disposal before first turning the disposal offAlso, remember the Prime Directive! asUse the spoon to try to turn the disposal wheel. If it doesn’t move, that’s good. If it does move and spins freely, you’ve got a problem—you might have a bad motor.

If the wheel doesn’t move with the spoon, but the motor still hums, there is probably something lodged in the wheel that is preventing it from spinning. Use a flashlight to look down the sink drain and see if there is anything jamming the wheel like a spoon or a fork (and, yes, these items sometimes do get caught in the garbage disposal!). See if you pry these out with a pair of pliers. 

If you can’t remove what’s jamming the garbage disposal, or can’t figure out what is jamming it, give us a call. Benjamin Franklin Plumbing can help diagnose the problem and propose the most cost-effective solution. All of our services are performed to a high professional standard and your satisfaction is guaranteed. 

Properly maintained (meaning you are following the tips above), a garbage disposal typically lasts 10 years or more. In most cases, when a garbage disposal has reached the end of its life, or it has been damaged to the point where it cannot be returned to normal operation using the steps above, it is simpler and less expensive to just replace the unit rather than try to repair it.

At Benjamin Franklin Plumbing Bay Area, we’re here to support you every step of the way to explore your options for repairing or installing a new garbage disposal system.  Contact us and talk to one of our plumbing experts.