Machine does not heat; brewing cycle will not start and display shows E01 shortly after power-on.

Safety first: Unplug the coffee maker and allow it to cool for at least 30 minutes before opening any panels. Never work on a live appliance.

• Power reset: Disconnect power for 5 minutes, then plug back in and try a rinse or brew cycle. If E01 returns immediately, continue.
• Check for obvious overheating: Smell for burnt odor around the thermoblock area (metal heating block inside). If there is a strong burnt smell, stop and contact a technician.
• Access the thermoblock: Remove the water tank and drip tray. Remove the top cover screws (usually under decorative caps or at the back). Carefully lift the top cover to expose the thermoblock assembly.
• Inspect wiring: Look for loose or burnt connectors on the thermoblock, NTC sensor leads, and thermal fuse. Reseat any loose push-on connectors firmly.
• Test the NTC sensor (if you have a multimeter): Disconnect the two NTC wires from the control board. Measure resistance at room temperature; most Zwilling thermoblock NTCs are in the 50–100 kΩ range at ~25°C. An open circuit (infinite resistance) indicates a failed sensor.
• Check the thermal fuse: The thermal fuse is usually a small cylindrical component attached to the thermoblock with heat-shrink or a clip. Test for continuity; if open, it has blown and must be replaced with the same rating.
• If NTC or thermal fuse is faulty: Replace the defective component or the complete thermoblock assembly if parts are not individually available. Reassemble the machine and test.
• If all components test good: The main control board temperature circuit may be defective. At this point, professional diagnosis or control board replacement is recommended.