Garbage disposal runs but water backs up into dishwasher

Safety first: Turn OFF power to the disposal and dishwasher.

• Step 1 – Inspect hose routing: Ensure the dishwasher drain hose runs from the dishwasher up to a high loop under the countertop or to an air gap before connecting to the disposal inlet.
• Step 2 – Add high loop: If missing, secure the hose to the underside of the countertop with clamps to create a high loop.
• Step 3 – Clear sink drain: Verify that the sink and disposal drain freely; clear any clogs in the P-trap or drain line.
• Step 4 – Test dishwasher: Run a short dishwasher cycle and observe for any backflow.

Warning: Backflow can contaminate the dishwasher; correct hose routing is essential.