Informational Guide

How To Wire A Garbage Disposal Switch & Outlet

Looking to install a new garbage disposal? Follow this simple step-by-step guide to learn how to wire a garbage disposal switch and outlet.

by Ian Haynes

Garbage disposals are one of those vital pieces of equipment which you just can't live without. They help protect your plumbing and keep everything moving like it should, giving you peace of mind which is really valuable.  

Installing a garbage disposal isn't too challenging, but wiring a disposal switch is quite technical and should not be attempted by anyone with limited experience. This guide will show you have to wire a garbage disposal switch and outlet, but this should not be done by amateurs as you could risk serious harm.  

Remember, our team at Plumbing Lab does not recommend that you attempt this DIY wiring if you don’t have the relevant experience of installing home electrics. You should consider hiring a professional to do the work for you.  

Garbage disposals attach to your sink and the drain line using a T connection. There are two types of garbage disposal, a continuous disposal and a batch feed. They both operate differently, and some of the components are different:  

  • Continuous Feed Disposals 
    Continuous feed disposals work to deal with any food waste put into them, and waste can be put in as it's running. You simply need to flip a switch, and they'll churn up anything that goes into them. It's vital they have a power outlet and a switch so you can turn it off and on as needed.  
  • Batch Feed Disposals 
    Batch feed disposals work slightly differently. You have to put in all of the food waste in one go and then switch it on; you can't just throw in waste while it's on. Batch feed disposals don't generally require a switch because there's a special drain plug that activates them when closed.  
Food Going Down Sink Garbage Disposal

Different Types Of Garbage Disposal Switches 

There are a few different types of disposals switches out there, and they all work slightly differently. It's worth taking the time to understand them, so you know what wiring work needs to be done.  

Air Switch 

Air switches don’t use any electricity and rely entirely on airflow. When you push a button, air flows through a tube and activates an air pressure switch. This turns the unit on, and when you press it again, it will turn it off. 

Air switches are great because there is no risk of electrocution, and you can install them anywhere. The downside is that they can be more expensive, and they are prone to corrosion.  

Wireless Switch 

Wireless switches use a remote control to send a signal to your disposal, turning it on and off as needed. They're handy, and it prevents you from having to drill into your worktop, but it's pretty easy to lose the remote control.  

Toe Kick Switch 

Toe kick switches allow you to use your garbage disposal completely hands-free. They are designed with a footswitch that sits underneath your sink and is used to turn the garbage disposal on and off. It's worth noting that toe kick switches can only be used with garbage disposals of 1 horsepower or less.  

Wiring A Switch Activated Garbage Disposal

Before You Start Wiring: Safety First 

Safety always comes first, and when electricals are involved, you can never be too careful. Here are some safety tips you must follow before you start work: 

  • Don’t Proceed Unless Confident! 
    Electrical wiring is not straightforward, and there is a serious risk of injury if you are electrocuted. If you don't feel confident, then you are better off hiring a professional. If you choose to proceed, you should be aware of the risks, and Plumbing Lab does not recommend that any non-professional attempt this work.  
  • Turn Off Power Sources 
    You must turn off the electricity supply before you start playing with wires. The safest way to do this is to go to your circuit breaker and turn off the switches for your kitchen.  
  • Remove Water   
    Turn off all water sources in the kitchen and make sure all faucets are closed. Dry off any moisture in the area before you begin work to help protect you from electrocution.  
  • Install GFCIs  
    Ground Fault Circuit Interrupters (GFCI) are required by law to protect you from severe electric shocks. There should be a test button on the outlet which stops the power immediately. If you don't have one, or it's not working, then you should get a professional to fit it for you.  
  • Qualified Electrician Review 
    Faulty wiring is a leading cause of domestic fires. It’s important you get a qualified, professional electrician to review your work once it’s complete so you can be sure you and your family are safe.  

How To Wire A Garbage Disposal Switch: Step-By-Step + Diagrams 

Ok, so wiring and home electrics are not always straightforward, but we've given a step-by-step guide below on how to go about it. Remember, your garbage disposal should be on its own 15–20-amp circuit.  

To wire the switch itself, you'll need: 

  • 12-gauge wire 
  • Wire cutters 
  • Utility knife 
  • Wire strippers 
  • Screwdriver 

1. Turn Off The Power 

Make sure your power is all turned off. Depending on your setup, you may need to turn off the electrical supply for the room or for your entire home. It's crucial you do this, or you could risk serious injury.  

2. Cut 4 Inches Of Wire  

Cut a piece of wire 4 inches long and set aside.  

3. Locate The Wires 

Locate your 12/2 and 12/3 wires coming from the bottom of your box. Use the utility knife to carefully slit about 2.5 cm from the edge to expose the 3 wires within each.  

Garbage Disposal Switch Wiring

4. Strip The Wires 

Use the wire strippers to take the insulation off the last ½ inch of the wire. Make sure you don’t cut the wire, or it will be too short, and make sure you don't strip off too much insulation, or you could risk an electrical fire.  

5. Attach Your Red Wire 

Hold your switch so that it's clear the on position is pointing upwards. Take your red wire and attach it to the brass screw at the top of the switch. Loop it around the screw and then tighten it to hold it in place. This red wire powers the disposal unit, so it's important it's connected to turn it on and off.  

Attach Your Red Wire

6. Attach The Grounding Wires 

Locate the green screw on the switch and the green wire from the box. Attach the green wire to the green screw and tighten it in place. This takes the electricity away from the disposal in case there's an electrical surge, so it's important to have this in place to mitigate any risk of electrical fires.  

Attach The Grounding Wires

7. Attach The Jumper Wire 

Take the black wire you cut in step 1 and attach it to the other brass screw. This will connect to the outlet itself and provide the power. Loop the wire around the screw and then tighten it in place.  

8. Secure The Black Cables 

Take the jumper cable and the black wires from the 12/2 and 12/3 cords and hold them together, so they line up. Twist them together and put a wire cap over the end to keep them all together. This will allow power to travel between the outlet and the device.  

9. Secure The White Wires

Locate all the white wires and twist them together. These will also attach to the outlet to complete the circuit. Use a wire cover to hold them all together.  

Secure The White Wires

10. Attach The Switch Plate 

Attach your plate with the switch on into the electrical box. Make sure all the wires are connected securely and pushed into the box, so nothing is protruding. Ensure everything is working correctly before you tighten it all up with screws. 

Your switch should not be located too near any water sources as this can be a hazard. You can legally put this switch in a nearby cupboard, and you should keep it 30cm away from the sink itself for safety.  


Where Is The Best Place To Put A Garbage Disposal Switch? 

Your garbage disposal should be located fairly near to your sink so you can switch it on and off while you’re using it. You need to avoid a wet area as there is a risk of electrocution. The best place to install it is the wall above the sink, making sure it’s at least 30cm away from the water source.  

Wireless garbage disposals use a push button or remote control, and these are generally waterproof. This means you can place them on the kitchen counter right next to the sink. Air switches don’t use any electricity, so these are safe to install anywhere, and many people opt to install them on the kitchen surface.  

Generally, the further away from water you install the garbage disposal switch, the safer it is. The best location is almost always on the wall behind the sink, 30cm away from the faucet.  


How To Wire A Garbage Disposal Outlet DIY

The garbage disposal and the switch will need to be wired to an outlet to work correctly. You will need a 120-volt outlet with a 20-amp circuit breaker for safety. Cord wires are generally the safest wires to use too. Here’s a step-by-step guide of what you need to do to wire your outlet. 

To carry out this work, you'll need: 

  • Needle Nose Pliers 
  • Wire Strippers 
  • Cord Wire 
  • Screwdriver 

1. Strip The Wires

Strip the insulation from the wires coming from the garbage disposal. You should look to strip about 2.5cm from the edge, any more, and it could become a hazard. Make sure you only work on a single wire at a time.  

Strip The Wires

2. Break The Tab

Make sure you’re using an outlet with three prongs and find the brass screws on the side. These should be connected with a metal tab. Use your pliers to remove it. It should snap off fairly easily.  

Break The Tab

3. Attach The Black Wire 

Locate the black wire and wrap it around the bottom screw on the side of the outlet. Tighten the screw to hold it securely in place.  

4. Attach The Red Wire 

Locate the red wire and wrap it around the top brass screw on the side of the outlet. Tighten the screw to hold it securely in place. 

5. Complete The Circuit 

The outlet will have a silver screw on the top left side. Loop the white wire around this and tighten it in place, looping the rest of the white wire behind so it sits in the electrical box. This wire is neutral and allows the circuit to be completed so electricity can flow.  

6. Ground The Outlet 

Locate the green wire and attach it to the green screw on the outlet, which is typically on the base of the outlet. Wrap it around and tighten the screw. This will ground the outlet and prevent any risk of injury.  

7. Attach The Outlet To The Electrical Box  

Ensure all your wires are in the electrical box and position the outlet, so it's just in front of them. Screw the top and bottom screws to secure it in place, but make sure you've tested the outlet first before tightening it all up.  

8. Test The Outlet 

Go to your circuit breaker and make sure the power is turned on. Make sure your disposal switch is all connected, and then connect your disposal. Turn it all on, and it should work. If there are any issues, you may need to ask a professional for help.  

Test The Outlet

Now that you've connected the switch and the outlet, your disposal should run. Remember that your outlet must be at least 30cm away from your sink to protect it from exposure to water.  


People Also Ask (FAQs)

Can a garbage disposal and dishwasher be on the same circuit? 

Yes, but make sure the total load doesn’t exceed 80% of the overall circuit capacity.  

Are garbage disposals hardwired or plugged in? 

Garbage disposals can be installed either way. Often an outlet is installed in the cupboard under the sink so it can be plugged in directly there. Whichever way it’s set up, you are best off with a dedicated circuit for the garbage disposal.  

Can refrigerator and garbage disposal be on the same circuit? 

A refrigerator should be on its own circuit and separate from the garbage disposal.  

How many amps does a garbage disposal switch require? 

They typically require 15-20 amps on a dedicated circuit.  

How much does Home Depot charge to install a garbage disposal? 

Home Depot charges between $100 and $150 to install a garbage disposal.  

What do plumbers charge to install a garbage disposal?  

Plumbers will typically charge between $80 and $200 to install a garbage disposal, but this may vary depending on your location.  Fill out the form below for a free quote!


Conclusion

Garbage disposals add a lot to your home, but they must be set up correctly. DIY wiring is never easy, but hopefully this guide has given you all the information you need to wire the disposal switch and outlet yourself.

Remember, do not attempt this without having the relevant experience and follow all safety tips. If you're not sure, you're better off consulting a professional as this is safer and ensures you'll get the job done right the first time.  

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.

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