What happened?

This warning appears when the Dwarf board toolhead’s microcontroller unit (MCU) exceeds its safe temperature range. The printer displays the message: "MCU in Dwarf is overheated, likely due to exceeding the printer's operating temperature. Prevent overheating for optimal performance".

Error name: DWARF_MCU_MAX_TEMP

Error code: #17826 (XL)

How to fix it?

This warning typically appears when the ambient temperature around the printer is too high, or when the printer is enclosed without proper ventilation. 

• Ensure the printer is used in an environment with ambient temperature below 30 °C (86 °F).
• If you're using a custom enclosure, ensure it has sufficient passive or active airflow to prevent heat buildup. Avoid sealed or poorly ventilated designs.
• The Original Prusa XL Enclosure is engineered for safe thermal operation. However, prolonged operation in an already warm room can still contribute to this issue.
  • Temporarily open the enclosure door to improve airflow.
• Allow the printer to cool down: turn it off and let it rest for at least 10–15 minutes before continuing.
  • With the printer fully cooled down, check for dust or obstructions around the toolhead that may trap heat.

If the issue persists even in a cool environment, contact our Support for further diagnostics, as the internal sensors or electronics may be faulty.