How to Replace a Garbage Disposal

Garbage disposals are workhorses that eventually reach their breaking point, usually signaled by persistent leaks, burnt-out motors, or an inability to clear simple food scraps. Replacing one isn't just about hauling away the old unit; it is about ensuring a watertight seal at the sink flange so you don't end up with cabinet water damage weeks later. Done well, this project is a clean, straightforward afternoon swap that restores your kitchen's utility without needing a plumber. The trick lies in managing the weight of the unit during removal and ensuring the discharge pipe aligns perfectly to avoid stress on the seals. Focus on the plumbing connections first, and the rest will fall into place.

  1. Kill the Power First. Unplug the disposal from the outlet under the sink and turn off the circuit breaker that controls the kitchen disposal. Place a bucket under the unit to catch any residual water or debris trapped in the P-trap.
  2. Disconnect Every Line. Loosen the nuts on the discharge pipe and the dishwasher drain hose. Carefully pull the plumbing away from the disposal, noting exactly where each gasket sits.
  3. Lift and Twist Free. Support the weight of the unit from the bottom with one hand while using a screwdriver to turn the mounting ring counter-clockwise. Once the ring unlocks, lower the unit away from the sink assembly.
  4. Seal the Flange Tight. Remove the old mounting assembly from the sink and scrape away the old plumber's putty from the drain opening. Apply a new rope of plumber's putty around the underside of the new flange and press it firmly into the sink drain.
  5. Lock It Down Solid. Secure the new mounting ring and snap ring to the underside of the sink using the included hardware. Tighten the three mounting screws evenly until the assembly is rock solid against the bottom of the sink.
  6. Secure and Reconnect. Lift the new disposal onto the mounting ring and rotate it until it locks into place. Reconnect the dishwasher hose and the discharge pipe, using new rubber gaskets if the kit provides them.