Swap a Kitchen Sink Garbage Disposal

Category: Plumbing · Difficulty: Intermediate · Time: 1.8h · Estimated cost: $175

Tools needed

Unplug or cut power
Unplug disposal under sink, or flip the breaker. Run the switch — confirm dead.
Duration: 5 min
Disconnect drain and dishwasher
Place a bucket. Loosen the slip nut at the P-trap. Pop off the dishwasher drain hose at the disposal inlet.
Duration: 15 min
Remove old disposal
Insert hex wrench in the lower mounting ring lugs. Twist counter-clockwise to release. Lower the unit into the bucket.
Duration: 15 min
Swap mounting flange (if needed)
If new disposal uses a different sink flange, remove the old one, scrape putty, install the new flange with plumber's putty.
Duration: 25 min
Knock out dishwasher plug or install plug
If you have a dishwasher, knock out the disposal's dishwasher inlet plug with a screwdriver. Otherwise leave it in.
Duration: 5 min
Wire and mount disposal
Wire the new disposal black-to-black, white-to-white, ground-to-green inside the access panel. Lift the disposal up into the mounting ring and twist clockwise to lock.
Duration: 25 min
Reconnect drain and test
Hook up the P-trap and dishwasher hose. Run water with disposal on for 30 seconds. Check every joint with a paper towel.
Duration: 15 min

ALWAYS cut power before reaching into the disposal — never bypass this step.
Disposals are heavy (8-15 lbs) — support with a knee or a 5-gallon bucket while twisting off.
Never use chemical drain cleaner before swapping — residue burns skin.

Hardwired disposal (no plug under the sink) — a plumber or electrician should redo the wiring properly.