Garbage Disposal Installation: The Ultimate Guide

A garbage disposal unit is a modern kitchen appliance that delivers eco-friendly solutions to food waste management.

With proper installation, a garbage disposal can grind food particles into pieces, reduce landfill waste, and make kitchen cleanup a breeze.

But do you know how to install a garbage disposal properly?

Don’t fret!

Throughout this expert guideline, I will walk you through step-by-step instructions that will help you install a garbage disposal like a pro.

So, let’s dive in.

Pre-Installation Considerations: What Should You Consider Before Installing A Garbage Disposal?
Safety Precautions: What Are The Safety Tips You Should Maintain During Garbage Disposal Installation?
Garbage Disposal Installation: A Step-by-Step Guideline
What Are The Common Challenges You Should Deal With When Installing A Garbage Disposal?
Garbage Disposal Post-Installation Maintenance Tips
FAQs
Conclusion

Pre-Installation Considerations: What Should You Consider Before Installing A Garbage Disposal?

To ensure a smooth and successful garbage disposal installation, take the following considerations into account:

Choosing The Right Garbage Disposal Unit

Selecting the appropriate food waste disposal unit is crucial to ensure optimal performance and longevity. Before choosing a garbage disposal, consider these criteria:

Horsepower: Typically, garbage disposal comes with various horsepower ranges, from 1/4 to 1 horsepower. Higher horsepower garbage disposal is recommendable for a household with heavy food waste.

Type: There are two main types of garbage disposal available in the market, including continuous and batch-feed garbage disposal. A continuous-feed garbage disposal is cheap and widely used in most kitchens. On the other hand, batch-feed garbage disposal is pricey and safe to operate.

Noise Level: Look for garbage disposals with sound insulation if noise is a concern.

Durability: Opt for a stainless steel garbage disposal over plastic garbage disposal to ensure durability.

I published a detailed guideline on how to choose a garbage disposal. Read that article, which will help you choose the best garbage disposal.

Checking Compatibility With Your Sink

Is the garbage disposal unit you choose compatible with your kitchen sink? Take the following criteria into consideration to verify the compatibility of the garbage disposal with the sink:

Space Under the Sink: How much space is there under the sink? Measure the space under the sink to ensure the garbage disposal fits perfectly.

Drain Size: The standard size of most kitchen sink openings is 3.5 inches in diameter, which is compatible with most garbage disposal units.

Mounting Style: Check which mounting style is compatible (3-bolt or EZ mount) with your kitchen sink.

Necessary Tools & Materials

Assemble all tools and materials to simplify the garbage disposal installation process.

Tools: Adjustable wrench, screwdriver (flathead and Phillips), pliers, and a putty knife

Materials: Garbage disposal unit, plumber’s putty

Understanding Local Plumbing Codes

Be well-informed about the local plumbing codes and regulations regarding garbage disposal installations:

Permits: 50% of US residents have garbage disposal installed in the kitchen. However, some areas in the USA may require permission to install a garbage disposal unit.

Waste Outlet: According to the 2021 Internal Plumbing Code (IPC), the garbage disposal unit should be connected to a drain of 1.5 inches in diameter.

Water Supply: You must attach your garbage disposal to a cold water supply. The water supply must be protected against backflow by an air gap or backflow preventer.

Electrical Requirements: A garbage disposal can be connected directly to a power source through hardwiring or plugged into a grounded electrical outlet. I suggest you check the disposal user manual to check the details of the electrical codes.

Environmental Regulations: Remember to check any restrictions on food waste disposal in your area, as some municipalities have specific guidelines.

Read Further: Garbage Disposal Code Requirements

Safety Precautions: What Are The Safety Tips You Should Maintain During Garbage Disposal Installation?

To reduce the risks associated with installing a garbage disposal and ensure safety, follow these safety precautions:

Electric Safety

Cut off the electric supply to your garbage disposal to ensure safety.
Avoid touching bare wires and verify that all wire connections are secure and insulated.
The food waste disposal must be grounded to reduce the risk of electric shocks in the event of a malfunction or breakdown.
If the garbage disposal you choose has a power cord, insert the power cord into a properly grounded electric outlet.
For hardwired garbage disposal, you must connect the disposal unit to a properly grounded, metal, permanent wiring system.

Plumbing Safety

To create a watertight seal, apply plumber’s putty around the sink flange.
Verify all connections, including the discharge tube, dishwasher tube, and mounting connections, are secure & tight.
Inspect the garbage disposal for leaks by running water once you complete the installation procedure.

Handling Sharp Parts

A garbage disposal has several sharp parts. For example, the impellers are a bit sharp. So, wear safety gloves when handling or removing the old garbage disposal.

Don’t hesitate to wrap the old garbage disposal in a thick plastic bag or cardboard before removing it.

Garbage Disposal Installation: A Step-by-Step Guideline

Once you gather all the tools and materials at your fingertips, it’s time to install the garbage disposal.

Follow the below step-by-step instructions to complete the garbage disposal installation procedure:

Step 1. Prepare The Work Area

Before beginning the workflow, turn off the power.

If the garbage disposal is hardwired, go to the circuit breaker box and find the circuit breaker for the disposal. Then, flip the circuit breaker down.

On the other hand, unplug the power cord from the electric outlet if you have a garbage disposal with a power cord.

Then, clean the area under the sink.

Step 2. Remove The Old Garbage Disposal Unit

Ensure you unplug the garbage disposal from the electric outlet.

Unscrew the discharge tube by removing the bolts

Then, go forward to unscrew the discharge tube. Use a Phillips head screwdriver and loosen the two bolts that secure the discharge tube in place.

Take out the two bolts and remove the discharge tube. Ensure you place a plastic bucket as there may be water spills in the P-trap.

Remove the dishwasher hose from the disposal inlet

Then, unclamp the dishwasher hose and remove it from the dishwasher inlet on the disposal.

Loosen the mounting assembly with the disposal wrench

Next, insert a screwdriver or the disposal wrench into a groove. Turn the wrench left. Ensure you support the disposal with the other hand. The disposal unit will drop right out.

Afterward, take the garbage disposal and put it right back in the old box.

Now, it’s time to remove the mounting assembly.

Regarding this, lay down on your back and unscrew the three mounting bolts. Before that, make sure you remove the snap ring. Then, pry off the mounting assembly to pull out the mounting assembly from the sink flange.

Finally, remove the sink flange from the top of the sink opening.

Step 3. Install the Sink Flange and The Mounting Assembly

Remove the old plumber’s putty from the sink opening. You can use a putty knife to scrape the plumber’s putty.

Then, use paper towels to clean the sink opening thoroughly by removing gunk and residue.

After cleaning the sink opening, unbox your garbage disposal unit and unscrew the flange from the mounting assembly.

Make a bowl with the plumber’s putty. Then, turn the bowl into a ring. Apply the plumber’s putty around the sink flange and install it by dropping it through the sink opening.

apply plumber's putty around the sink flange

Put a weight on the sink flange.

Under the sink, slide the fiber gasket through the sink flange. Then, insert the backup flange and the mounting ring into the sink flange. Hold the backup flange and the mounting ring in place while inserting the snap ring.

Secure the mounting ring against the backup flange by tightening the three bolts.

hook up the mounting assembly to the sink flange

Now, go to the top of the sink opening and scrape the excess plumber’s putty.

Step 4. Connect the Electrical

In this stage, attach the power cord to the garbage disposal.

Regarding this, flip down the garbage disposal and remove the wire cover plate. Pull out the two wires.

Install the adapter and thread all the power cord wires through it. Tighten up the adapter to secure the wiring.

Then, unscrew the ground nut and secure the ground wiring with the disposal unit. Then, match the wire colors, connect the remaining wiring, and secure them with wire nuts.

After that, replace the wire cover plate and tighten it with the provided nut.

Now, focus on taking out the garbage disposal knockout plug. It is essential because I need to connect the dishwasher drain hose to the disposal unit.

To remove the knockout plug, use a flathead screwdriver and insert it into the disposal inlet. Then, hammer it down to knock out the plastic plug. Pull out the plug from the grinding chamber.

Remove the disposal dishwasher plug from the inlet

You can check out this article if you are still confused and don’t know how to wire a garbage disposal with plug-in cord.

Step 5. Attach the Garbage Disposal To The Mounting Assembly

connect the garbage disposal to the mounting assembly

Verify that you slide the splash guard in the lip of the garbage disposal unit.

Lift the disposer from the bottom, (1) hang the disposer by aligning 3 mounting tabs on the lower mounting ring with slide-up ramps on (G), and slightly turn the disposer.

Using the disposal wrench, turn the lower mounting ring until all 3 mounting tabs latch over the ridges on the slide-up ramps.

Step 6. Connect the Garbage Disposal To The Plumbing

Connect the dishwasher drain hose to the disposal inlet. Just slide the dishwasher hose into the disposal inlet and secure the hose by tightening the clamp nut.

Next, slide the gasket into the disposal outlet. Then, insert the flange into the discharge tube and attach the discharge tube to the disposal by securing it with the nuts.

Afterward, connect the discharge tube to the P-trap or the drain line.

Step 7. Check for Leaks & Test the Disposal Unit

Finally, it’s time to check the garbage disposal for leaks and test it by operating the disposal unit.

Restore the electric power to your garbage disposal.

Finally, run the cold water supply and turn on the garbage disposal. Go down and check for leaks.

What Are The Common Challenges You Should Deal With When Installing A Garbage Disposal?

Here are some common challenges when installing a garbage disposal and how you can overcome them:

Tight Spaces Under The Sink

Working in a tight space under the sink is one of the most common challenges you should deal with when installing a garbage disposal.

The room under the sink is limited, which makes it challenging to maneuver the garbage disposal unit and connect the plumbing & electrical to it.

How You Can Overcome This Challenge:

Organize the under-sink area.

To make space for installation, clear out items stored under the sink, like cleaning products.

Try to use more compact, maneuverable tools that fit in the tight space. Nonetheless, look for a compact garbage disposal designed for installation in a smaller space.

Misaligned Plumbing

Misalignment of the existing plumbing can lead to complications during installation. If the plumbing is not aligned properly, it can result in an incorrect connection and potential leaks.

To avoid the misaligned plumbing issue:

Before installing the garbage disposal, inspect the sink drain and check the old plumbing connections. Then, align the plumbing connection to the disposal unit according to the old alignment.

Verify that you use flexible or adjustable flex connectors to facilitate realignment of the plumbing in case of misalignment.

Don’t hesitate to adjust or reposition the existing pipes (if required) to ensure a proper fit for the new food waste disposer.

Electrical Wiring Issues

You can face electrical wiring issues, especially if the existing wiring is outdated or incorrectly configured.

To mitigate the electrical wiring issues:

Inspect the old electrical wiring and the outlet to verify that they meet safety standards.

Call a certified electrician if you are unsure about wiring or face complications.

Addressing Leaks And Blockages

After installation, you can encounter issues like disposal leaks and blockages.

Check all the connections and seals for tightness to prevent leaks. Use a plumbing snake to remove clogs from the garbage disposal unit if you experience a restriction.

Garbage Disposal Post-Installation Maintenance Tips

Many homeowners believe the myth that a garbage disposal unit doesn’t require maintenance. But the reality is- you should maintain the disposal unit regularly to keep it functional for a long time.

Here are some garbage disposal maintenance tips & best practices you should focus on after installing the food waste disposer:

Regular Cleaning and Upkeep

To keep the disposal unit efficient and prevent odors, perform these regular cleaning practices:

Run the disposer regularly: Operate the garbage disposal two to three times a week to keep the disposal unit functional and prevent internal components from rusting.

Clean the disposal regularly: Clean the food waste disposer every week. You can use vinegar or ice cubes to clean the garbage disposal unit.

Read: How To Clean Garbage Disposal

Use a disposal cleaner: Periodically use a garbage disposal cleaner or deodorizer to clean built-up grime and prevent foul odors.

What Not To Put In A Garbage Disposal

Avoid these certain items from putting in the garbage disposal:

Fibrous food: Never put fibrous or stringy foods, including celery, corn husks, and asparagus, down the garbage disposal unit.

Hard items: Avoid putting hard objects such as bones, seeds, pits, or shells into the garbage disposal.

Grease and oil: Never pour grease, oil, or fat down the disposal, as they can solidify and cause clogs.

Expandable foods: Don’t put expandable foods, such as pasta, rice, and bread, into the garbage disposal as they can swell and clog the disposal.

Explore Further: What Not To Put In A Garbage Disposal

Troubleshooting Common Problems

Even with proper installation and maintenance, you may still encounter issues with your garbage disposal unit. Here are some common garbage disposal problems and their solutions:

Disposal doesn’t turn on: Verify that you plug the garbage disposal into the electric outlet. Then, check the circuit breaker and ensure it doesn’t get tripped. Lastly, press the reset button to revive your garbage disposal unit.

Jammed Garbage Disposal: Get the disposal wrench and slide it into the hole at the bottom of the unit. Then, rotate the impellers manually to release the restrictions.

Leaking garbage disposal: Check the connections for tightness. Apply the plumber’s putty to seal the sink flange properly or tighten the mounting screws.

FAQs

How much does it cost to install a garbage disposal?

Installing a garbage disposal will cost you $512. The cost includes the price of the garbage disposal itself and the labor cost. Factors like the size and horsepower of the disposal unit, brands, installation complexity, and labor costs affect the total installation cost.

Read Further: Garbage Disposal Installation Cost

How long does garbage disposal installation take?

On average, a professional installer requires two to four hours to install a garbage disposal. The time frame includes removing the old garbage disposal, installing the new one, and reconnecting the plumbing connections.

On the other hand, if you replace the old garbage disposal with the same model, it will take one to three hours.

For those considering DIY installation, the time it takes to install a garbage disposal will depend on your experience and your comfort with plumbing and electrical work.

Can I install a garbage disposal on my own?

Yes, you can install a garbage disposal on your own if you have the right tools and guidance. Most homeowners find the garbage disposal installation as a manageable DIY project. Fortunately, this ultimate guide shows how you can install a garbage disposal. Follow the step-by-step guidelines and install the disposal unit yourself without hiring a pro.

Conclusion

Installing a garbage disposal unit is simple. Follow these key installation steps:

Turn off the power to the unit and clean the under-sink area
Remove the old garbage disposal
Clean the sink opening and install the sink flange
Connect the mounting assembly to the sink flange
Wire the disposal properly
Attach the garbage disposal to the mounting assembly
Reconnect the plumbing lines
Test for leaking

Prioritize safety during the installation process to prevent accidents and guarantee a seamless installation experience.

Don’t hesitate to seek professional assistance if you encounter challenges that exceed your comfort level- such as complex plumbing adjustments or electrical issues.

Or, you can get our comprehensive garbage disposal manual. It helps you install, repair, and maintain the garbage disposal unit.

Get Our Garbage Disposal Manual Now

Related Articles:

Resource Links:

https://codes.iccsafe.org/content/IPC2021P1/chapter-4-fixtures-faucets-and-fixture-fittings#IPC2021P1_Ch04_Sec416
https://www.nachi.org/garbage-disposals.htm
https://www.youtube.com/watch?v=_u9ulIo5Xfc
https://insinkerator.emerson.com/documents/power-75hp-installation-care-use-manual-en-us-10267284.pdf

Sohel

Sohel Rana is the founder of FixTheDisposal.Com. He is a plumbing expert with 7+ years of hands-on repairing garbage disposals, water heaters, space heaters, and other appliances used in a home. Before the launch of Fix The Disposal, he wrote and provided advice on water heaters, sump pumps, and space heater repairing & troubleshooting tips for LilDutchUncle.Com.

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