Prusa 13208 on a MK4 3D printer: hotend MINTEMP error

Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.

1. 1

   Stable room temperature

   No special tools

   Who:

   you.

   How:

   look at where the printer sits: Prusa asks for a stable ambient temperature above 18 °C.

   Result that matters:

   whether the room is cold or draughty.

   If it is cold or draughty:

   move the printer or fix the room before trying again.

   If the room is fine:

   the cause is in the printer.

   Evidence to keep:

   room temperature and time.

   Evidence: Prusa Knowledge Base: Hotend mintemp error #31208 (CORE One) #35208 (CORE One L) #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)

2. 2

   LoveBoard cables in view

   No special tools

   Who:

   you, if you follow Prusa's guide for your model.

   How:

   with the printer cold and off, access the LoveBoard (on the MK4 the cover slides upward) and check whether the heater and thermistor cables are properly connected and undamaged along their length.

   Result that matters:

   seated connectors and uncut cables.

   If you see a loose connector:

   reseat it with the printer off.

   If you see a damaged cable:

   do not repair it yourself; ask for the part.

   Evidence to keep:

   photos of the LoveBoard and cables.

   Evidence: Prusa Knowledge Base: Hotend mintemp error #31208 (CORE One) #35208 (CORE One L) #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)

3. 3

   Note when it appears

   No special tools

   Who:

   you.

   How:

   write down whether the error shows with the printer just switched on in a cold room, mid print or when the toolhead moves.

   Result that matters:

   whether it matches cold or movement.

   If it matches toolhead movement:

   it points to a damaged cable; tell the technician.

   If it matches a cold room:

   fix the room and try again.

   Evidence to keep:

   notes with date, time and room temperature.

   Evidence: Prusa Knowledge Base: Hotend mintemp error #31208 (CORE One) #35208 (CORE One L) #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)

A code is meaningful only inside the right product and version context.

Prusa explains this error appears when the nozzle temperature drops below 5 °C at any point, and that if it happens during a print, the print stops. The screen asks you to check the print head thermistor wiring for damage. Prusa first asks for a stable ambient temperature above 18 °C and, if it is not the cold, puts the error down to the hotend thermistor. It also asks you to check the cables at the LoveBoard, the extruder fuse and the main cable. It is 26208 on the MK4S and 31208 on the CORE One.

• Criticaleditorial warning

  Do not disable or bypass the thermal protection or change the firmware to clear the alert: it is what cuts the heat when the temperature does not add up. Do not open the printer's power supply or mains board: anything at mains voltage is for the service team.

  Evidence: Prusa Knowledge Base: Hotend mintemp error #31208 (CORE One) #35208 (CORE One L) #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)

• Highsource verified

  Prusa asks for the printer to be cooled down and switched off before you access any part or electronic board. The nozzle and the bed burn while they are hot.

  Evidence: Prusa Knowledge Base: Hotend mintemp error #31208 (CORE One) #35208 (CORE One L) #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)

1. 1

   Prusa Knowledge Base: Hotend mintemp error #31208 (CORE One) #35208 (CORE One L) #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)

   Prusa Research · 2026 · official_doc