Thermomix displays C1 and refuses to start heating or cooking functions.

Safety first: Disconnect power and let the appliance cool for at least 30 minutes before inspection.

• Power cycle and cool down: Unplug the unit, remove the bowl, and allow the machine to cool fully. After cooling, plug back in and check if the C1 error clears.
• Check for blocked ventilation: Ensure the Thermomix has adequate space around it and that the underside and rear vents are not blocked by cloths, plastic, or debris. Overheating can trigger sensor faults.
• Visual inspection (advanced): With the unit unplugged, remove the bottom cover and inspect the heater block area. Look for burnt wiring, melted insulation, or a dislodged sensor clipped to the heater block. Reseat the sensor connector on the PCB.
• Service recommendation: If the error persists, the overheat sensor or the main board must be tested with a multimeter and replaced if out of specification. This involves working near mains-voltage components and should be done by a qualified technician.