A broken or leaking garbage disposal can stop your kitchen work right away. Replacing this unit might seem like a complex plumbing job that needs a professional. However, for most homeowners, this is a straightforward repair that you can do in an afternoon. This guide will walk you through every necessary step to successfully finish this common home project.
The process of how to replace a garbage disposal? involves disconnecting the old unit, removing the mounting assembly, installing a new flange, and then connecting the new appliance. By following clear instructions and focusing on safety, you can save money on a service call and regain use of your sink quickly. You will see that replacing garbage disposal is much easier than you think.
What Is a Garbage Disposal?
A garbage disposal, also often called a food disposal or food disposer, is a device installed under a kitchen sink between the drain and the trap. Its job is simple: it shreds food waste into tiny pieces. These small particles then wash away through the plumbing system. The unit uses spinning impellers, or small metal pieces, inside a grinding chamber to turn solid food into a liquid-like slurry. This prevents large chunks of food from clogging the kitchen’s drain pipes.
Most units attach to the sink opening using a special three-bolt mounting system or a simpler snap ring system. For many homes, the unit also includes a connection for the dishwasher drain hose, which lets food and dirty water from the dishwasher empty into the disposal before heading to the sewer line. Knowing what the unit does and how it attaches is the first step to knowing how to change food disposal when the time comes.
Is It Easy to Replace a Garbage Disposal? (Expectation vs. Reality)
A common question is, is it easy to replace garbage disposal? The direct answer is yes, for a replacement job, it is quite easy for a homeowner with basic tools. It becomes more challenging if you are installing a new unit where one never existed before, as this involves running new electrical lines. However, a simple unit-for-unit swap is one of the most common and simple plumbing-related DIY tasks.
Key Factors That Make it Easy:
- Standardized Mounting: Most major brands use a universal three-bolt mounting system. This means if you buy a new unit that matches the style of your old one, the hard part of the plumbing is already in place.
- Pre-existing Wiring: If your old unit was plugged into an outlet, replacing the garbage disposal unit is simply a matter of unplugging the old one and plugging in the new one (after some quick wiring to the new unit’s power cord).
- Waste Pipe Alignment: If you choose a similar size and brand, the main drain pipe connection often lines up almost perfectly with the new unit. This avoids the need to cut or adjust PVC drain pipes.
The hardest parts are often dealing with the unit’s weight it can be heavy and awkward under the sink and the tight space. But overall, it is a project that requires simple tools and clear steps, not expert plumbing skills. This guide will show you how replace garbage disposal without trouble.
Safety First: Essential Prep Before You Begin
Before you even touch a wrench, safety and preparation are the most important steps. This expertise ensures you avoid electrical shocks and massive leaks. Ignoring these steps is a recipe for trouble.
- Turn Off the Power: This is non-negotiable. Find your home’s main electrical panel (breaker box). Flip the breaker switch that controls the kitchen sink or disposal. To be certain, go back to the sink, flip the disposal wall switch on, and confirm the unit is completely dead. If your unit is plugged into an outlet under the sink, unplug it. Never work on the unit with power on.
- Clear the Space: Remove everything from under the sink. You will need room to move, lay on your back, and put down a bucket.
- Gather Supplies: Put all your tools, the new unit, and materials within easy reach. The last thing you want is to be stuck under the sink and needing a wrench that is across the room.
- Water Management: Place a large bucket directly under the old disposal’s drain pipes. When you disconnect the plumbing, water and sludge will spill out. Use old towels or rags to protect the cabinet base.
Tools and Materials Needed to Replace a Garbage Disposal
Having the right tools ready makes the job much smoother and quicker.
| Tool/Material | Purpose |
| New Garbage Disposal Unit | The replacement unit. |
| Plumber’s Putty | Used to create a watertight seal around the sink flange. |
| Flathead Screwdriver | Used to pry off the snap ring and turn the mounting ring. |
| Phillips Head Screwdriver | Used for the electrical plate cover and mounting screws. |
| Adjustable Wrench or Pliers | For loosening and tightening the plumbing connections (drainpipes). |
| Garbage Disposal Wrench | A special tool, often included with the new unit, to lock the disposal onto the mounting ring. A screwdriver can work in a pinch. |
| Bucket and Rags | To catch water and drain sludge from the pipes. |
| Wire Nuts and Electrical Tape | For safely connecting the electrical wires (if hardwired). |
| Safety Glasses | Protect your eyes from falling debris or water. |
Step-by-Step: Removing the Old Garbage Disposal
This is the removal phase. Take your time to get each connection completely free.
1. Disconnect the Plumbing
- P-Trap/Drain Line: Look for the pipe that runs from the side of the disposal into the wall drain. This is the discharge tube. Use your adjustable pliers or wrench to loosen the slip-nut or coupling connecting the discharge tube to the disposal. Let the trapped water drain into your bucket.
- Dishwasher Connection (If Applicable): If you have a dishwasher, a smaller hose connects to the side of the disposal. Loosen the clamp or nut holding this hose and pull it off. Be ready for a small amount of water to leak out here as well.
2. Disconnect the Electrical Wires
The most delicate part of replacing garbage disposal is the wiring.
- Unplugged Units: If your unit is plugged into an outlet, you simply remove the plug. Skip to step 3.
- Hardwired Units: Locate the metal plate on the bottom of the disposal. Unscrew the cover. You will see three wires: green (ground), white (neutral), and black (hot). Carefully unthread the wire nuts to disconnect the corresponding wires from the home’s supply. The unit is heavy, so do this while it is still attached to the mounting ring. Set the wires safely aside.
3. Release and Remove the Unit
The old disposal is held up by a mounting ring right under the sink.
- Support the Weight: Place a stack of wood or a small car jack under the unit to help support its weight. Disposals are heavier than they look.
- Twist Off: Insert a garbage disposal wrench or a large flathead screwdriver into one of the three lugs (small arms) on the lower mounting ring. Twist the ring sharply counter-clockwise until the unit drops free from the mounting assembly. Be ready to take the full weight of the unit as it separates. Place the old, heavy unit aside. This is a crucial step in how to replace the garbage disposal.
4. Remove the Mounting Assembly and Flange
Now you must remove the old hardware still attached to the sink drain.
- Snap Ring: Under the sink, you will see a snap ring holding the mounting ring in place against the sink bottom. Use your flathead screwdriver to pry the snap ring off. It might be sticky.
- Remove Parts: Once the snap ring is off, the remaining parts the mounting ring, fiber gasket, and metal backup ring will slide down.
- Clean the Sink Drain: The last piece is the sink flange in the drain opening. Pop it out from above the sink. Scrape off all the old, dried plumber’s putty from the sink rim with your putty knife or screwdriver. The sink must be perfectly clean and dry for the new seal to work.
Step-by-Step: Installing Your New Garbage Disposal Unit
How to change garbage disposal moves now to the installation phase. Start with the new unit’s components.
1. Install the New Sink Flange
- Plumber’s Putty: Roll a rope of plumber’s putty, about a half-inch thick, and press it around the underside rim of the new sink flange.
- Place Flange: Drop the flange into the sink drain opening, putty-side down. Press down hard. Wipe away the excess putty that squeezes out from above the sink.
- Secure from Below: From underneath the sink, slide the fiber gasket, the metal backup ring, and the upper mounting ring onto the flange tail. Use your flathead screwdriver to secure the new snap ring into the groove on the flange. This locks the assembly into place.
2. Connect the Power Cord
- Knockout Plug (If Needed): If you have a dishwasher, you must remove the knockout plug from the new disposal’s dishwasher inlet. Tap a hammer and screwdriver against the plug until it falls into the grinding chamber. Reach in and take out the plastic piece. If you skip this, your dishwasher will not drain.
- Wire the Unit: If your unit is hardwired, open the electrical plate on the bottom. Connect the wires from the house to the corresponding wires on the new disposal using wire nuts (black to black, white to white, and green or bare copper to the green ground screw). Replace the cover.
3. Mount the Disposal
- Lift and Hang: Lift the new unit. Align the three mounting tabs on the disposal’s neck with the lower mounting ring.
- Twist to Lock: While supporting the weight, twist the lower ring clockwise until the mounting tabs lock firmly into place. If your new unit came with a special wrench, use it now to turn the ring until you feel the unit fully seat and lock with a firm click. The disposal outlet should be facing the direction of your drain pipes. Getting the unit to lock correctly is the key to successful replace disposal.
4. Reconnect the Plumbing
- Discharge Tube: Attach the main discharge tube to the disposal outlet, using the rubber gasket and flange provided with the unit. Tighten the slip-nut securely with your wrench.
- Drain Pipes: Reconnect the rest of the drain plumbing (the P-trap) that leads to the wall.
- Dishwasher Hose: Reattach the dishwasher hose and tighten its clamp.
How Long Does It Take to Replace a Garbage Disposal?
The total time spent on this project can vary based on your skill level and how well the old parts cooperate. Generally, how long does it take to replace a garbage disposal? The answer is that it can take a confident DIYer about 90 minutes to 3 hours from start to finish.
An experienced plumber can often do it in under an hour, especially if the new unit matches the old one perfectly. For you, the time is mostly spent on the details: scraping off old putty, wrestling with the weight of the old unit, and ensuring all the new connections are completely water-tight. Do not rush the plumbing test at the end a slow, careful check for leaks saves time later.
You can read about: How to Install a Garbage Disposal Unit
Conclusion
Replacing a garbage disposal is a rewarding and highly practical skill that every homeowner can master. By carefully following the steps for disconnecting the plumbing and electrical, removing the heavy old unit, and installing the new sink flange and unit, you can solve a major kitchen problem without paying for a service call. The depth and practical steps in this guide show you exactly how to replace the garbage disposal the right way.
If you are replacing a disposal or need any complex plumbing work near Garbage Disposal Eagle Rock, the professional team at Derks Plumbing is ready to help. We are experts in all kitchen and bath repairs. We can quickly handle any plumbing issues you may not feel comfortable doing yourself, ensuring a perfect, worry-free installation.
FAQs
Q1: What is the most important safety step when changing a garbage disposal?
The most important step is cutting the power. Always go to the main circuit breaker and flip the correct switch to the “Off” position. You are dealing with water and electricity in a tight space, so confirming the power is off is vital to avoid electric shock.
Q2: What is the purpose of plumber’s putty?
Plumber’s putty is a soft, non-hardening compound used to seal joints between two surfaces. In this case, it is placed under the sink flange to create a watertight seal between the flange’s metal edge and the ceramic or stainless steel of the sink basin. This keeps water from seeping through the drain hole and into your cabinet.
Q3: How do I know when it is time for a garbage disposal replacement?
The unit is likely due for replacing a garbage disposal unit if you see any of the following: a major leak from the bottom of the unit (often a sign of a cracked casing or rusted internal seals), a continuous humming sound without grinding (motor failure or a severe jam that can’t be cleared), or if it constantly trips your circuit breaker.
Q4: Can I just use my old mounting assembly with the new unit?
If the new unit is from the same manufacturer or is specifically labeled as using the same standard mount (like an EZ Mount or three-bolt system), then yes, you may be able to just twist the new unit onto the old assembly. However, for the best seal and longest life, it is always recommended to remove the old assembly and use the brand-new one provided with your purchase. This avoids future problems with leaks when you are replacing a garbage disposal.
