Garbage disposal stops when dishwasher drains, E12 backflow/overload code on combo-installed Tweeny models

Safety First: Turn OFF power to the disposal and dishwasher before working on hoses.

• Step 1 – Inspect dishwasher hose: Ensure the hose from the dishwasher to the Tweeny disposal has a high loop under the countertop or uses an air gap fitting.
• Step 2 – Check inlet nipple: Remove the dishwasher hose from the disposal inlet and inspect for plastic knockout remnants or food blockage. Clear as needed.
• Step 3 – Verify knockout removal: On new installations, confirm the plastic knockout plug inside the dishwasher inlet on the Tweeny unit has been fully removed.
• Step 4 – Test separately: Run the disposal and dishwasher drain cycles separately to see if E12 only occurs during combined operation. If so, the circuit may be overloaded and require a dedicated disposal circuit.

Correct hose routing and a clear inlet usually resolve E12. If the breaker trips or overload persists, consult an electrician.