Machine does not heat; coffee button lights may blink rapidly and brewing will not start

Safety first: Unplug the Nespresso machine and let it cool for at least 30 minutes before opening any covers. Hot internal parts and live mains voltage are present.

Basic checks (no disassembly):

• Confirm the water tank is full and properly seated; some models will not heat if the tank is not detected.
• Descale the machine if it has not been descaled recently; heavy scale can cause overheating and trigger protection.
• Power-cycle the machine: unplug for 10 minutes, then plug back in and try again.

Intermediate checks (requires opening the housing):

• Remove the outer cover according to the service manual for your specific Nespresso model.
• Locate the thermoblock assembly (aluminum block with water tubes and heater terminals).
• With a multimeter (machine unplugged), measure resistance across the heater terminals. An open circuit (infinite resistance) indicates a failed heater or blown thermal fuse.
• Inspect the thermal fuse mounted on or near the thermoblock. Test for continuity; if open, it must be replaced with the same temperature and current rating.
• Check the NTC temperature sensor (usually clipped to the thermoblock). Measure its resistance and compare to service specs; a shorted or open NTC can cause Error 1.
• Inspect wiring connectors to the heater and sensor for heat damage or loose connections; reseat or replace as needed.

When to stop: If the heater is open or the thermoblock is cracked or heavily scaled internally, replacement of the entire thermoblock assembly is recommended. If you are not comfortable working around mains wiring, contact a qualified appliance technician.