Garbage Disposal Installation 15 Step Guide

Once you've experienced the convenience of the garbage disposal in your home, it's hard to go without it when it stops working.

Many people value their garbage disposal’s ability to dispose of food waste and help keep pipes clear of clogs. Still, most types of garbage disposals experience wear and tear after a decade or more of grinding up scraps and leftovers. Whether you have one that needs replacing, or you've just bought one for the first time, garbage disposal installation can be a relatively simple process.

In this guide, we’ll cover:

• Garbage disposal lifespan
• How to remove a garbage disposal
• How to install a garbage disposal
• How to replace a garbage disposal
• Common questions about garbage disposal installation

How Long Do Garbage Disposals Last?

Sometimes it can be hard to tell whether you simply have a broken garbage disposal that needs a little love and repair, or if it's time to replace it. These appliances tend to last about ten years but may not last that long if used frequently or not properly maintained.

Signs You Need a New Disposal?

Here are some signs that it is time for a garbage disposal replacement or that you may need help from a repairperson.

• Abnormal noises Suppose you hear a strange noise when you run the garbage disposal, and you don’t see an object in the drain that could cause it, such as silverware. In that case, the disposal components are probably misaligned. This will cause the impellers to grind together when you run the garbage disposal and means the entire unit needs to be replaced
• Frequent resets If you must reset your garbage disposal frequently, then this is a clear sign that your appliance is aging out.
• Inexplicable clogs You should wash food particles down the drain in small amounts. If you notice that even the tiniest food particles are jamming the appliance, this is a sign that you need a new garbage disposal.
• No power If your garbage disposal is not turning on, or is shutting itself off while in use, you should schedule a garbage disposal inspection immediately. This is a sign that the motor has failed.
• Persistent odors If you are rinsing and cleaning and nothing is getting rid of the odors coming from your garbage disposal, you might need professional assistance. Your plumber can take the garbage disposal apart to see what is causing the issue and determine if your disposal needs to be replaced.
• Planned renovation If you are already planning a kitchen renovation, this is a great time to replace your garbage disposal.
• Poor performance If it takes a long time for your garbage disposal to break down food particles, the unit might need replacing.
• Water leaks If you see water leaks, you should confirm if they are coming from the seal between the sink and the disposal. If the leak is from the seal, then you can replace and reseal the gasket at little cost. Likewise, replacing a leaky hose is not very costly. If the leaks are coming from the unit itself, then you probably need a full garbage disposal replacement.

How to Remove a Garbage Disposal

Once you've determined it's time to replace your unit, it’s relatively simple to remove an unwanted garbage disposal in several easy steps: Note: If you're installing a garbage disposal for the first time, you can skip to the steps for installation

1. Power Down the Unit

Shut off the power supply to the disposal by unplugging its power cord from the wall socket or turning off the circuit breaker. Keep in mind that some garbage disposals are hardwired, so you will need to disconnect the wires before going any further. If you have a multimeter, you can use it to ensure no power is running through any of the wires.

2. Loosen Hose Connections

Loosen the hose clamp attaching the dishwasher hose to the disposal nipple and remove the hose.

We recommend placing a bucket under the waste pipe to catch any wastewater remaining in the pipes or hoses.

3. Remove the P-Trap

Use an adjustable wrench, pipe wrench, or pliers to remove the fittings on the p-trap, which is a U-shaped pipe connected to the garbage disposal. Remove the trap and allow water to drain into the bucket.

4. Detach the Disposal from Connections

Disconnect the garbage disposal from the pipework by either unscrewing it from the sink drain or removing the snap ring with a flat-head screwdriver.

5. Remove the Disposal

Detach the mounting assembly and lift the disposal out of place. Now, you’re done removing the disposal unit.

How to Install a Garbage Disposal

Once you have removed your old garbage disposal, you can start the replacement process. Fortunately, garbage disposal installation doesn't require advanced plumbing knowledge. Be sure to read your new disposal owner's manual for helpful installation tips and guidance.

1. Gather Your Materials

Purchase a new garbage disposal that meets your size, speed, and noise-level requirements.. Then gather your tools, including:

• Hacksaw
• Screwdriver
• Plumber’s putty
• Garbage disposal wrench
• Water pump pliers
• Electrical cord
• Safety supplies

2. Power Down

Ensure that the circuit breaker to the garbage disposal is turned off. Even if you’re installing a new unit after removing the old one, it’s recommended to double-check that the breaker is off.

3. Ensure a Drain Flange is Installed

Install a new drain flange in your sink, if necessary, before wiring or mounting the new garbage disposal. You can check your owner's manual for instructions, but you'll typically coat the bottom of the new flange in the plumber's putty and insert it into the drain until it's secure. Place a rubber seal on the drain flange underside. Then, place another rubber seal on the bottom of the sink and attach the metal backup ring.

4. Secure the Mounting Ring

Install a new mounting ring. Unless you bought the same make or similar model of garbage disposal as your old one, you’ll typically need a new one. Make sure the flange and ring are lined up closely. Loosely attach the mounting ring with three screws, secure the mounting ring with the snap ring to snap it into place, then tighten the three screws. It's recommended you alternate tightening each of the three screws bit by bit to ensure a snug fit. Tighten until excess plumber's putty begins to seep out; however, don't overtighten, as this will squeeze out too much of the putty and you won’t get an adequate seal.

5. Prepare the Disposal for Placement

Prepare the new garbage disposal and place it under your sink, but don't mount it just yet.

6. Connect to Power

Plug in or wire your new disposal. Some models simply plug into an outlet under your sink, while others need to be hardwired. If hardwiring is required, consult your owner's manual, but you'll typically want to match the wire colors on your disposal with the ones coming from under the sink.

7. Mount the Garbage Disposal

Lift the disposal onto the mounting bracket and lock it into place. Make sure the opening of the discharge pipe, or P-trap, aligns with your sink's drain waste trap before locking the mount.

8. Connect the Pipework

Attach the discharge pipe to the disposal with a gasket and screws, then slide the other end into the drainage pipe under your sink. If necessary, also remove the dishwasher knockout plug from the new unit and connect the dishwasher line.

9. Check for Leaks

Run water through the disposal once everything looks fastened and secure to ensure there are no leaks.

10. Power Up

Turn the power back on at the circuit box. That's it; you now know how to replace a garbage disposal!

Contact First American Home Warranty

What is a home warranty? First American home warranty coverage gives homeowners peace of mind. A home warranty with garbage disposal coverage can save you money and time spent under the sink installing a new unit.

FAQs About How to Install a Garbage Disposal

How long do garbage disposals last?

Even if you know how to repair a garbage disposal, most only last for ten years, on average. How much does it cost to replace a garbage disposal? Roughly $200 to $550 but can be on the lower end of that range if you choose a simpler model and install it yourself.

Is replacing a disposal hard?

No, replacing garbage disposals doesn't require any major plumbing or electrical experience. However, certain features will require extra steps when you’re learning how to install a garbage disposal. For example, choosing a model that plugs into an outlet (if you have one under the sink) will save you the trouble of hardwiring it.

Can I install a garbage disposal by myself?

Yes. With this handy guide, installing a garbage disposal for the first time should be relatively straightforward. Just remember to follow all safety precautions and double-check for water leaks before using your newly installed disposal.

What do I need to install a garbage disposal for the first time?

Though you don't need many tools for the job, some of the essentials are specialty items designed for working on garbage disposals. It's a good idea to gather:

• Hacksaw
• Screwdriver
• Plumber’s putty
• Garbage disposal wrench
• Water pump pliers
• Electrical cord
• Safety supplies like work gloves and goggles

How do you hook up a sink drain to a garbage disposal?

Sink drains are connected to garbage disposals by a discharge pipe, also called a P-trap. There will be a large opening on your disposal for one end of the discharge pipe, and the other end of the pipe will be inserted into the opening for the drain waste trap under the sink. You may need to use a hacksaw to modify the length of the pipe if it doesn't match the size of your old, broken garbage disposal.

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The contents of this article are provided for general guidance only. First American Home Warranty does not assume any responsibility for losses or damages as a result of using this information.

Please be aware that if you disassemble a covered system or item, it can invalidate your home warranty or manufacturer's warranty.