Prusa error 13208 (Hotend Mintemp Error) appears on the MK4 and is reported as #26208 on the MK4S, #21208 on the MK3.9, #27208 on the MK3.9S, #31208 on the CORE One, and #35208 on the CORE One L. The firmware detected a nozzle temperature reading below 5°C at any point during operation — an impossibly cold reading that indicates a sensor failure rather than genuine thermal conditions.

What the Error Means

A sub-5°C thermistor reading does not reflect the actual nozzle temperature in any normal operating environment. This error nearly always points to a broken thermistor, a completely disconnected thermistor connector, or a severed thermistor wire that causes the input to float to a voltage the firmware interprets as a very low temperature. A room temperature genuinely below 18°C can occasionally push the reading close to the threshold on a marginal thermistor, but a healthy sensor in any normal indoor environment will not report below 5°C.

Step-by-Step Fix

1. Verify ambient temperature. Confirm the printer is operating in a room warmer than 18°C. Very cold workshops can exacerbate marginal thermistor connections.
2. Power off and cool before touching components. Although the printer reports a cold temperature, allow any residual heat in the heater block to dissipate below 40°C before handling the LoveBoard or cables.
3. Inspect LoveBoard heater and thermistor cables. Access the LoveBoard for your model — on MK4/S and MK3.9/S, slide the extruder cover upward; on the CORE One, use a T10 Torx driver to remove the panel. Check the thermistor connector is fully seated and that neither the thermistor wire nor the heater cable shows cuts, kinks, or burn marks.
4. Check the LoveBoard main cable at the xBuddy board. Trace the cable from the extruder to the board and look for pinch points where movement could intermittently break a conductor. On MK4/S models, also check the extruder protection fuse inside the xBuddy enclosure — a blown fuse can affect circuit readings.
5. Measure resistance with a multimeter. With the printer off and cooled, probe the thermistor. An open circuit (infinite resistance) or a near-zero reading confirms a failed thermistor. A healthy NTC 100k thermistor reads approximately 100 kΩ at room temperature.

Parts Required

• Replacement NTC 100k thermistor (most common fix)
• Replacement extruder protection fuse (MK4/S, MK3.9/S — verify correct rating)
• Digital multimeter
• T10 Torx screwdriver (CORE One)

If replacing the thermistor and reseating all connections does not resolve the error, contact Prusa Support — an internal LoveBoard fault is uncommon but possible.

Frequently asked questions

What does Prusa 13208 mean?

Prusa error 13208 (Hotend Mintemp Error) appears on the MK4 and is reported as #26208 on the MK4S, #21208 on the MK3.9, #27208 on the MK3.9S, #31208 on the CORE One, and #35208 on the CORE One L. The firmware detected a nozzle temperature reading below 5°C at any point during operation — an impossibly cold reading that indicates a sensor failure rather than genuine thermal conditions.

How do I fix Prusa 13208?

Prusa error 13208 means the nozzle temperature dropped below 5°C. Fix thermistor disconnection, LoveBoard cable issues, and cold ambient conditions.