MCU in Modular Bed is overheated

What happened?

The Modular Bed Control Unit (MCU) monitors temperature to ensure the printer operates within safe limits. When the internal temperature exceeds a defined threshold, the printer displays a warning "MCU in Modular Bed is overheated. Any higher will result in fatal error".

Error name: MOD_BED_MCU_MAX_TEMP

Error code: #17827 (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.
• If you're using the Original Prusa XL Enclosure, no immediate action is needed; it is engineered for safe thermal operation. However, prolonged operation in an already warm room can still contribute to this issue.
• Allow the printer to cool down: turn it off and let it rest for at least 10–15 minutes before continuing.
• Minimize continuous long-duration prints at high bed temperatures, especially in warm environments.

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