Moen garbage disposal causes water to back up into the opposite sink basin

Safety first: Turn off and unplug the disposal. Do not run the dishwasher until the drain is clear.

• Confirm the pattern:
  • Run water in the non-disposal basin and observe if it backs up into the disposal side.
• Clean the trap and tee:
  • Place a bucket under the sink.
  • Remove the P-trap and any baffle tee or cross-connection between basins.
  • Clear all sludge and debris.
• Snake the wall drain:
  • Use a hand auger to clear the drain line in the wall where the trap connects.
• Reassemble correctly:
  • Ensure the baffle tee is oriented per Moen/pipe manufacturer instructions to prevent cross-flow.
• Test both basins:
  • Run water in each basin separately and together to confirm proper drainage.