Cycle ends prematurely with E03; dishes are not fully washed and water may be left in the tub.

Safety: Turn off power at the breaker and close the water supply tap before working on the appliance.

E03 indicates the water is not heating correctly.

• Check if water heats: Run a short hot program and open the door mid-cycle (after 10–15 minutes). If the water is cold and E03 appears, suspect the heater circuit.
• Access heater: Remove the dishwasher from the cabinet and take off the base panel. Locate the flow-through heater or circulation pump with integrated heater on the side or base.
• Inspect wiring: Check the heater terminals and wiring harness for discoloration, burning, or loose connectors. Reseat all plugs.
• Measure heater resistance: Disconnect the heater terminals. With a multimeter on Ω, measure across the heater. Typical values are 15–30 Ω. An open circuit (OL) indicates a failed heater.
• Control board relay: If the heater tests OK, inspect the main control module for a burnt heater relay or tracks. Replace the power control module if damage is found.
• Replace faulty part: If the heater is open or leaking, replace the Neff flow-through heater or circulation pump/heater assembly as per your model.

Reassemble, restore power and water, and run a test cycle to confirm proper heating.