Garbage disposal causes water to back up into the dishwasher.

Safety first: Turn off power to both appliances and avoid running the dishwasher until the issue is resolved.

• Step 1 – Clear disposal outlet: Remove the discharge elbow and clean any food buildup.
• Step 2 – Inspect dishwasher inlet: Remove the dishwasher hose from the disposal and check for obstructions at the inlet and in the hose.
• Step 3 – Verify high loop/air gap: Ensure the dishwasher hose is routed in a high loop under the countertop or through an air gap to prevent backflow.
• Step 4 – Clean air gap: If present, remove the air gap cap and clean any debris.
• Step 5 – Test: Reconnect everything and run a dishwasher drain cycle to confirm water no longer backs up.