Dishwasher will not start; display shows E01 shortly after pressing Start.

Safety first: Disconnect the dishwasher from mains power by switching off the circuit breaker and unplugging if accessible. Do not work on live circuits.

E01 on many Neff dishwashers indicates a serious fault with the main control electronics.

• Power reset: Turn off the breaker for 5–10 minutes, then restore power and try a short cycle. If E01 returns immediately, continue below.
• Check for water in base: Remove the plinth/kick plate. Use a torch to inspect the base tray. If you see water, dry it with towels or a sponge. Do not run the machine until the leak source is found (see leak-related entries).
• Inspect wiring harness: With power off, remove the left or right side panel (depending on model). Check the harness from the mains filter to the main control module for burn marks, melted insulation, or loose connectors. Reseat all plugs firmly.
• Check control module: Access the main control (usually in the base or behind the right side panel). Look for burnt components or a burnt smell. If visible damage is present, the module must be replaced.
• Replacement: If wiring and base are dry and intact but E01 persists, replace the Neff power control module with the exact part number from the rating plate or existing board. This job often requires removing the appliance from the cabinet and should be done by a qualified technician.

If you are not comfortable working around mains voltage or removing panels, contact a professional.