Water backs up into the opposite sink basin when the Project Source disposal runs (on a double sink)

Safety first: Turn off power to the disposal before working on the plumbing.

• Check for visible blockage: Remove the strainer from the non-disposal basin and look for obstructions.
• Clean trap and tee: Disassemble the P-trap and the baffle tee connecting both basins. Clean out grease and food buildup.
• Snake the line: If the piping under the sink is clear, use a small drain snake into the wall stub-out to clear further obstructions.
• Reassemble and test: Reinstall all fittings, run water in both basins, and then operate the disposal to confirm that water no longer backs up.