Kitchens are usually happy places, full of the smell of delicious cooking and good cheer. That is, until you flick the switch of your garbage disposal and hear only a hum, or worse, the sound of metal grinding on metal! A damaged garbage disposal is sure to have you reaching for the phone, calling your plumber to install a new one.

But hold on just one minute! If you’re handy around basic tools, replacing a garbage disposal is an easy DIY project. Doing it yourself will also save you some cash. All you’ve got to do is follow these home plumbing hacks and learn how to replace a garbage disposal.

Remember though, that while the job may be easy, it does involve being in an uncomfortable position for a period of time which may put stress on your back. So if you have back problems, you may be better off hiring professional help.

How to replace a garbage disposal: The process

Make sure the disposal needs to be replaced

replacing a garbage disposal

Before you run off to the store to buy a new garbage disposal, make sure the one you have at home is actually beyond repair.

There are two main things you need to check before you write off your current garbage disposal.

Turn on the switch. If nothing happens, check the power outlet. This is usually located underneath your sink. Check if the plug has been accidentally dislodged.

If that seems to be intact, the built-in circuit may have tripped. You can reset the circuit by pushing the little red button located at the bottom of the unit. If that still doesn’t start the motor, it’s time to buy a new disposal.

If you hear a hum or a grinding noise when you turn on the motor, it may be that a peach pit, a piece of glass, or some other material is blocking the blades. This even happens when fibrous foods such as celery wrap themselves around the blades. The first thing you need to do is turn off the power to the unit and then, shine a flashlight to look into the unit. If you spot the obstructing object, use a pair of pliers or a long fork to take it out.

Remember, never make the mistake of sticking your fingers down the disposal. Those blades are sharp enough to take your fingers clean off.

Turn the garbage disposal unit on again. If you’re still hearing only a hum, head out to buy a new one.

Get the tools ready

You will need some very basic tools to replace the garbage disposal unit in your kitchen. Here’s a list of what you’ll need.

  1. Flat-head screwdriver
  2. Plumber’s putty
  3. Putty knife
  4. Needle nose pliers
  5. Philip’s head screwdriver
  6. Hammer
  7. Flashlight

Removing the old unit

As with the case of working with any electrical appliance, you ought to first turn off the power to your garbage disposal before you begin taking it apart. Begin by unplugging the power outlet, which ought to be located either underneath the sink or on the wall near your kitchen countertop

Next, turn off the power to that garbage disposal from your home’s main circuit breaker. Normally, garbage disposals share a circuit with the dishwasher. If you’re unsure of which one it is, an easy way to find out is to turn either of the appliances on and flip the circuits one by one until it switches off.

  1. Clear out everything you may have stored underneath your sink and lay down an old towel to catch drips. Then, set up a flashlight so you have sufficient visibility while working.
  2. You will see a rigid PVC or metal pipe that carries the waste and water from your sink into the plumbing. This is called the discharge tube. Unscrew it and give it a gentle tug to displace it.
  3. If you have a dishwasher drain pipe, remove that as well. This is usually positioned above the discharge tube. 
  4. Next, locate the mounting ring, which is a thin metal ring with extending grips situated on top of the garbage disposal. Grasp the grips in one hand and rotate it counterclockwise while supporting the disposal with your other hand.

Read more: How to remove a dishwasher

Loosening the ring will free up the disposal. 

  1. Unscrew the metal faceplate found at the bottom of the disposal.
  2. The disposal’s copper grounding wire will be held in place by a green screw. Slip the wire from underneath it, and then use the needle-nose pliers to help you unclip the two electrical wires connecting the disposal to your home’s electrical system.
  3. After setting aside the garbage disposal, remove the rubber snap ring from inside the mounting bracket’s flange. Also, remove the old mounting bracket as well.
  4. Loosen the sink flange by pushing it up. You may need to tap it lightly with a hammer for it to be removable. Remove it from the sink above by pulling it up.
  5. Remove any old putty remaining around the sink’s drain using your putty knife. You are now ready to install the new garbage disposal.

Installing the new garbage disposal

new garbage disposal
  1. Start off by applying the plumber’s putty to the underside of the new sink flange. Press the flange into place, making sure its ring covers your kitchen sink’s drain opening. Secure it in place while the putty hardens by placing the old garbage disposal on it.
  2. Slide the new garbage disposal’s rubber gasket onto the new mounting bracket. Screw on the bracket underneath the sink.
  3. Attach the new mounting ring to the bracket by either sliding it in or screwing it in place, depending on the model.
  4. Unscrew the metal cover plate at the bottom of the new disposal. Then, attach it to your home’s electrical system by securing the copper grounding wire underneath the green screw. Next, clip on the electrical wires to their color-coded wire nuts on the disposal. The colors to look for will either be red and black or black and white.
  5. If your disposal needs to connect to the dishwasher, use a hammer to gently knock out the plastic plug for where the dishwasher needs to be connected.
  6. Secure the new garbage disposal in place by lifting it into position and holding it with one hand while you turn the mounting ring clockwise until it clicks in place.
  7. Reconnect the discharge tube and if needed, the dishwasher drain hose.
  8. Your putty ought to have dried by now, so take your old disposal off the sink flange. Turn on the water in your sink. If you’ve installed the disposal properly, there should be no dripping.
  9. Plug in your new garbage disposal. Turn on the circuit, and watch as your new disposal runs flawlessly.

Read more: How to clean garbage disposal

How to replace a garbage disposal: Costs and savings

Low-powered disposal can be as cheap as $50, with the more powerful, full-sized ones with extended longevity retailing at around $200. Most people settle for middle variants, spending between $75 and $100.

While that may not be much of a cost, hiring a professional to handle the installation, which usually takes a couple of hours, will put you down around $100 an hour. You could easily save that money by installing the garbage disposal yourself as a DIY project.

How to replace a garbage disposal? was last modified: November 24th, 2022 by Narayan Shrouthy
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“Make sure the disposal needs to be replaced”, haaaa haaaa haaaa, this is the funniest obvious fact you can write down for a home maintenance dedicated blog