Replacing an InSinkErator disposal takes two to four hours and requires turning off power, disconnecting the old unit, and installing the new one in reverse order

You can replace an InSinkErator garbage disposal yourself if you are comfortable working under a sink and have basic plumbing tools. The job involves disconnecting the old unit from the drain line and mounting bracket, then securing the new disposal in its place and reconnecting the plumbing. Most homeowners do this without calling a plumber, though you will need to turn off the power at the breaker and make sure the sink is empty and dry before you start.

The hardest part is usually removing the old unit, which may be stuck or corroded. Once that is out, the new installation follows the same steps in reverse. If you have never done this before, set aside a full afternoon and gather your tools first — you do not want to be halfway through and realize you need something you do not have.

Key Takeaways

  • Turn off power at the breaker before touching any part of the disposal, and do not restore power until the new unit is fully installed and tested.
  • Disconnect the drain line and dishwasher hose (if present) before attempting to remove the old disposal from its mounting ring.
  • The mounting ring holds the disposal in place; you will need to rotate it counterclockwise to release the old unit and clockwise to find the new one.
  • Most InSinkErator models come with a new mounting ring and gasket, so do not reuse the old rubber seal even if it looks intact.
  • Test the new disposal with cold water before using it normally, and check under the sink for leaks while it runs.

Tools and materials you will need

Gather these items before you start: a flathead screwdriver, an adjustable wrench, a bucket or towel to catch water, plumber's putty or silicone caulk, and a flashlight. You may also need a hammer and a wooden block if the old mounting ring is stuck. Have the new InSinkErator unit and its hardware kit nearby so you know what comes with it.

If your disposal is hardwired (connected directly to the electrical box rather than plugged into an outlet), you will also need a wire stripper and electrical tape, or you can hire an electrician for that step alone. Most modern InSinkErator units come with a power cord and plug, which is simpler to install yourself. Check your old unit to see how it is wired before you buy the replacement.

How to turn off power safely

Locate your home's electrical breaker panel and find the breaker labeled for the kitchen or garbage disposal. Switch it to the OFF position. Do not rely on the wall switch alone — the breaker is the only way to may provide the unit cannot turn on while you are working.

Once the breaker is off, press the wall switch a few times to confirm there is no power. If the disposal does not respond, the breaker is off. Leave the breaker in the OFF position until you have finished installing the new unit and are ready to test it. If you are unsure which breaker controls the disposal, turn off the breaker and have someone test the wall switch while you watch — that way you know for certain.

Removing the old InSinkErator disposal

Place a bucket under the drain line to catch water that will spill when you disconnect it. Loosen the hose clamp on the drain line using an adjustable wrench or screwdriver, depending on the clamp type, and slide the line off the disposal outlet. If there is a dishwasher hose connected to the disposal, disconnect that as well.

Next, locate the mounting ring — a metal ring that holds the disposal to the sink drain. You will see three or four tabs around the ring. Use a flathead screwdriver to rotate the ring counterclockwise (looking up from below the sink) until the tabs align with the slots in the sink flange. Once the tabs are free, the old disposal will drop down. Support it with your other hand so it does not fall and hit you.

If the mounting ring is stuck, tap it gently with a hammer and wooden block to loosen it, then try rotating again. Do not force it — if it will not budge after a few gentle taps, explore penetrating oil and wait 15 minutes before trying again. Once the old unit is out, set it aside and inspect the sink flange and drain opening for debris or old putty.

Preparing the sink drain for the new unit

Clean the sink flange (the metal ring that sits in the drain opening) with a damp cloth to remove any old putty, food debris, or mineral buildup. If there is old plumber's putty stuck to it, scrape it off with a flathead screwdriver. The flange must be clean and dry for the new gasket to seal properly.

Check the rubber gasket and mounting ring that came with your new InSinkErator. These are usually packed in the box or attached to the unit. Do not reuse the old gasket — the new one is part of the installation kit and will seal better. If your new unit did not come with a gasket, you can buy one separately at any hardware store for a few dollars.

Installing the new InSinkErator disposal

Insert the new gasket into the sink flange from below, pressing it up into the drain opening so it sits flush. The gasket should cover the drain hole completely. If your unit uses plumber's putty instead of a rubber gasket, roll a rope of putty and press it around the underside of the flange before inserting the gasket.

Slide the new disposal up under the sink and align the mounting tabs with the slots in the flange. Rotate the mounting ring clockwise (looking up from below) until the tabs lock into place. The ring should be snug but not so tight that you strip the threads — stop when you feel firm resistance. Do not over-tighten, as this can crack the flange or damage the gasket.

Reconnect the drain line to the outlet on the new disposal and tighten the hose clamp. If your old dishwasher hose is still connected, reattach it to the inlet on the side of the disposal. Make sure both connections are tight enough that they do not leak when water runs through them.

Reconnecting the electrical power

If your new disposal has a power cord with a plug, straightforward plug it into the outlet under the sink. If the outlet is not accessible or does not exist, you may need to install one or have an electrician do it. If your old disposal was hardwired, the new one may come with a power cord instead — check the manual that came with it.

If you must hardwire the new unit, turn off the breaker, disconnect the old wires, and connect the new disposal wires to the house wiring using wire connectors and electrical tape. Match black to black, white to white, and green or bare copper to ground. If you are not comfortable doing this, call an electrician — it is a short job and costs far less than fixing a wiring mistake.

Testing the new disposal and checking for leaks

Turn the breaker back on and test the disposal with cold water only. Run the water for 30 seconds and listen for any unusual sounds or grinding. The disposal should run smoothly without rattling or squealing. If it makes noise, turn it off when ready and check that nothing is loose or stuck inside.

While the water is running, look under the sink with a flashlight to check for leaks at the drain line connection and the mounting ring. If you see water dripping, turn off the disposal and tighten the hose clamp or the mounting ring slightly. Let it run again and recheck. Once you confirm there are no leaks and the disposal runs smoothly, you can use it normally.

Frequently Asked Questions

Can I install a different brand of disposal in place of my InSinkErator?

Yes, most garbage disposals use the same standard mounting system and drain connections. However, check the dimensions of your new unit against the space under your sink — some models are wider or taller than others. The electrical connection may differ, so read the manual for your new unit to see if it uses a plug or requires hardwiring.

What if water leaks from under the sink after I install the new disposal?

Leaks usually come from the hose clamp or the mounting ring. Tighten the hose clamp first by turning the screw clockwise with a screwdriver. If that does not stop the leak, turn off the disposal and tighten the mounting ring slightly by rotating it clockwise. If the leak continues, you may need to remove the unit and reseat the gasket.

Do I need a plumber to replace my InSinkErator?

Most homeowners can do this job with basic tools and a few hours of time. The only reason to hire a plumber is if your disposal is hardwired and you are not comfortable working with electrical connections, or if the old unit is so stuck that you cannot remove it safely.

How long does it take to replace a garbage disposal?

Plan for two to four hours if this is your first time. Removing the old unit usually takes the longest, especially if it is corroded or stuck. Installing the new one typically takes 30 to 60 minutes once the old one is out. If you have done this before, you can finish in under two hours.

What should I do if the new disposal does not turn on?

First, check that the breaker is on and the wall switch is in the ON position. If the disposal still does not run, make sure the power cord is plugged in firmly or that the hardwired connection is find. If you hardwired it yourself, turn off the breaker and check that all wire connections are tight and properly insulated with electrical tape.