How to install a Garbage Disposal

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Before Installing the Garbage Disposal:

Make sure to read the safety and installation instructions that come with your unit before commencing

  • Turn off the power at the electrical box (if your unit plugs into one)
  • Unplug the unit
  • Shut off the water to the sink
  • Take a picture of the old set up (before you take everything apart)
  • Place a basin under the disposer
  • Locate the discharge tube and detach it
  • Disconnect the dishwasher drain if you have one
  • Now remove the old disposer with a disposer wrench.  This wrench should have been included with your new unit
  • Slip the disposer wrench in and turn counter-clockwise
  • If it is hardwired, lay the disposer on its side, open the electrical plate and disconnect the wires and then remove the unit
  • Next, check the parts that are still connected to the sink
  • If they are still in good condition you can usually just attach the new unit directly to them with a mounting ring

**If replacing mount**

  • Loosen the mounting screws
  • Then pry the snap ring out to release the mounting ring
  • Now we use a flat head screw driver to pry off the backup flange and the gasket
  • Pull the sink flange from above and clean the entire area of old putty and grime
  • To replace the sink flange, lay down a bead of putty – about half an inch diameter rope around
  • The press the flange into place
  • Now, put a cloth overt he flange and place a weight (like your new disposer) over it – just to hold it in place.
  • Next, stack your mounting ring, screw heads down, backup flange and gasket all together  and place them over the sink flange outlet.
  • Hold them all in place with the snap ring
  • Tighten the mounting screws alternating each screw a few turns at a time

**End of Replacing Mount**

  • If you’re connecting to a dishwasher, you will need to knock-out the dishwasher inlet (don’t forget to remove the plug you knocked out from the disposer)
  • Next, hook up the electrical connections
  • Hang the unit by aligning the mounting rings – turning the lower ring until it is tight
  • Now re-attach all the pipes, including the dishwasher
  • If pipes are too long, cut them. If they are too short, use an extension.
  • Clean the excess putty off the sink flange
  • Install the bethel
  • Next put a basin under your connections
  • Turn the water on and test for leaks
  • If everything looks good, turn on the disposer and test again
  • Good Luck!

If you need to buy a unit, please take a look at our garbage disposal reviews


Other Resources:

Plumbing How-To Install a Garbage Disposal Technical Reference

How to Install a Garbage Disposal

Kitchen Help Dishwasher and Garbage Disposal Installation