Bialetti digital espresso machine displays E03 and does not heat; no steam or hot water is produced.

Safety first: Unplug the machine and let it cool completely. Heating components can retain dangerous voltage and high temperature.

• Power reset: Disconnect the machine from mains for at least 10 minutes, then reconnect and test. Sometimes transient sensor errors clear with a full power cycle.
• Descale the machine: Severe scale can cause hot spots and trigger overheat protection. Run a full descaling cycle with an approved descaler, following Bialetti's instructions.
• Check ventilation: Ensure the machine is not enclosed in a tight cabinet and that vents are not blocked. Overheating can be aggravated by poor airflow.
• Inspect thermoblock area (advanced): Remove the cover to access the thermoblock. Look for a small thermal fuse or thermostat clipped to the block. If it appears burnt or cracked, it may be open and require replacement. Also inspect wiring to the NTC sensor.
• Test continuity (advanced): With a multimeter and the unit unplugged, test continuity across the thermal fuse and heating element. An open reading indicates a failed component that must be replaced, not repaired.

If E03 persists, the thermoblock assembly or its sensor circuit likely needs professional replacement.