Heater error (on heated-extraction models), water not heating or heater symbol flashing

Safety: Unplug the unit. Heater components can remain hot; allow to cool fully before touching.

• Check power mode: Ensure the heater function is actually enabled on the control panel and that you are not in a cold-rinse mode.
• Descale the system: Run a descaling solution (approved for Miele) through the clean water tank and solution circuit to remove limescale that can cause overheating and sensor errors.
• Inspect heater block: Access the heater assembly and check for signs of overheating, discoloration, or leaks.
• Test thermal cut-out: Many heaters have a manual-reset thermal cut-out. If accessible, press the reset button gently. If it immediately trips again, there is an underlying fault.
• Professional testing: The heating element and NTC sensor should be tested with a multimeter. If open-circuit or out of specification, replace the heater assembly or sensor.