Machine powers on but does not heat; water comes out cold or lukewarm

Safety: Unplug the machine and allow it to cool before opening. Heating circuits carry mains voltage.

• Confirm symptom: Run a shot or hot water and measure the temperature at the outlet; if it remains close to room temperature, the heater is not operating.
• Check for descaling: If the machine has not been descaled, run a full descale cycle; heavy scale can reduce heat transfer, though a completely cold output usually indicates an electrical fault.
• Internal checks (advanced):
  • Access the brew thermocoil and inspect wiring and connectors.
  • Check for obvious burn marks or broken wires.
• Repair: Replace the brew thermocoil assembly if the element is open-circuit. If the thermocoil tests good, suspect the main PCB heater driver and seek professional repair.