Informational Guide

How to Replace a Garbage Disposal - DIY Installation

This complete step by step replacement guide will help you to mount a new food waste system

by Holly Curell

Your garbage disposal can be one of the most useful tools in your home. When it's functioning properly, it will help keep your kitchen clean and hygienic and help protect your plumbing from blocking. Unfortunately, when your garbage disposal isn't working, it can cause a whole host of problems.

If your garbage disposal becomes damaged or broken, you'll need to consider replacing it. This guide has all the necessary information to help you replace your disposal quickly and safely.

best 1/2 hp garbage disposal

Garbage disposals see a lot of use, and you might be used to dealing with clogs, but when do you need to replace a garbage disposal?

There are some telltale signs that your garbage disposal has given up the ghost even if it's still technically working day-to-day. 

Firstly, you’ll be experiencing blockages more often. This is a result of the blades getting duller and unable to deal with the waste. 

You’ll also find that waste takes longer to process even if it is still working. Bad smells will also become more common with faulty devices. This is a result of built-up waste and some old materials which aren't as easily cleaned.

Finally, you should look out for leaking around the device and if the garbage disposal becomes louder. These are both signs that it’s struggling to operate and could need to be upgraded.

Depending on the model, a garbage disposal’s lifespan could be up to 12 years. However, if you start to experience the above symptoms, you should seriously consider replacing the unit.

Garbage Disposal Replacement Cost

If you’ve decided you need to replace your garbage disposal you need to be careful to avoid spending too much. First, you should browse the market for models. Typically you can find garbage disposals for between $100 and $400, with the higher end models offering more features.

If you want to get the best value for money you should consider a model that suits your needs. The power of the motor should be determined by how many people are in your home. As a rough guide:

  • ⅓ or ½ HP: suitable for a small house or apartment with 1-3 people
  • ¾ HP: perfect for families with 4-6 people
  • 1 HP: able to take care of a family of 7-9 people
  • 2 HP: 2 HP is powerful and can handle food waste for more than 9 people.

By finding a model that suits your home, you'll see a longer lifespan, which ultimately means better value. You should also consider looking for solid materials like stainless steel. These will add to the durability of the disposal and mean greater value for money.

When it comes to garbage disposal replacement costs, you also have to consider the installation. If you're comfortable with DIY, you can probably do this yourself, but if not you can get a plumber to do the work. This will typically cost between $100 and $200 depending on your local options.

Tools Required to Replace a Garbage Disposal

Before replacing your garbage disposal, you should make sure you have all the tools you need beforehand. Your exact requirements may vary depending on your model, and some manufacturers might have specific tools they provide themselves.

A hacksaw and a hammer are useful to have but might not be needed in every kitchen. A wrench is essential for loosening the bolts, and you find a specific wrench for garbage disposals on Amazon here. You should also look to get a hex wrench, also available on Amazon here.

Plumbing Tools Needed

Other than these you should definitely have a good screwdriver and some reliable pliers nearby before you start the work.

You may well have a lot of these in your home already but getting tooled up beforehand is the secret to success with all DIY.

How to Replace a Garbage Disposal

Turn off the power supply to the garbage disposal

There is a live current running through your garbage disposal, and you'll need to make sure it's completely off so you can replace it safely. You can turn off the disposal underneath the sink, but you should also switch it off at the breaker. Flip the fuse switch off and then test the system to make sure it's entirely off before moving onto the next step.

Take Out the Disposal Unit

Once you find the pipe feeding into the compact garbage disposal, you should use a screwdriver to disconnect it. You should then be able to pull it free from the unit. You can then take hold of the unit and twist it anticlockwise to disconnect it. You should lay this down on an old cloth to stop any mess. Be careful because some disposal units will weigh up to 15 pounds so that you may need some assistance removing it.

Replace the mounting ring

Start by pulling away from the rubber ring and then the rest of the mounting ring should come away as well. You should then put a new rubber ring into position and attach the new mounting ring. Use a screwdriver to tighten all the screws in place.

New Hardware Installation

Lift the new disposal unit and carefully place the top underneath the mounting ring. You can then twist the disposal, so it fixes into place, tighten any screws that come with the unit. At this point, you should check the device to make sure it's in place securely.

Getting the new disposal ready

Shift your disposal so that the discharge tube lines up with the water pipes. Cut some PVC plumbing pipes so that the connection fits properly and remember to use a nut to lock this in place. This should make the disposal ready for use.

Check the wiring

Most garbage disposals will come with plugs built in that you just need to connect to your power, but some will need to be wired in. If this is the case, you should open the hatch at the bottom and connect the colored wires into a plug cord. Plug cords may not be included, but you can buy them separately fairly easily. If you have no experience with electricity, then you should be an expert to verify the work.

Completing the Installation process

To complete the installation process, you should run through all the steps to install a garbage disposal. You should run water through the device to make sure there are no leaks, and once you're satisfied, you should switch all the power back on again.

You can find a complete guide to replacing a garbage disposal in the video below:

Extend Garbage Disposal Life

A reliable garbage disposal, if well maintained, can last 12-15 years if properly maintained. There are some steps you can take to prolong the lifespan of your disposal and help you get better value for money.

Regular cleaning, daily, weekly, and monthly will help to keep your disposal functioning. A deep clean every few weeks where you remove all the waste and grease that's built up will help it to work well and also avoid any bad smells coming from your drains. You should feed some lemon peel in every so often to keep it smelling fresh.

When using the disposal you should always run cold water. This helps in the break up of waste and keeps it flowing through the system. You should let the disposal run for at least a minute after feeding the waste into it to make sure it’s all broken up.

Finally, you should make sure that you are only putting the right things into your disposal. Plumbers know all too well that some households treat their garbage disposal as a trash can, but you should only ever use it for food, and you should avoid large bones, fibrous foods like banana peels, and any grease or fat down the drain.


A garbage disposal is a powerful tool that can make your life at home much easier, but only if it works. By knowing what the signs are for a broken disposal, and how to replace it, you can ensure you keep getting all the benefits in your home.

Holly Curell is the editor extraordinaire for Plumbing Lab. Having grown up in Michigan, Holly has spent time living in New York, Virginia, & currently North Carolina, where she lives with her husband & family. Holly loves DIY & has years of experience with at-home plumbing problems that arise from having 3 kids & living in colder climates. When she's not writing about her plumbing knowledge, Holly enjoys reading, hiking & relaxing with family.