Prusa error 13207 (Bed Mintemp Error) appears on the MK4 and its equivalents are #31207 on the CORE One, #26207 on the MK4S, #27207 on the MK3.9S, #21207 on the MK3.9, #28207 on the MK3.5S, and #23207 on the MK3.5. The printer detected a bed thermistor reading below 5°C — a value so low it almost certainly indicates a disconnected or broken thermistor rather than the bed actually being that cold.

What the Error Means

When a thermistor is disconnected, its circuit reads as open, which most NTC thermistor input stages interpret as an extremely high resistance — corresponding to an extremely low temperature on the lookup table. The Buddy board interprets this sub-5°C reading as a Mintemp fault and halts all printing activity as a safety measure. The cause is nearly always a loose connector at the xBuddy board, a pinched or severed cable somewhere along the thermistor’s routing path, or, less commonly, a failed thermistor bead itself.

Step-by-Step Fix

1. Power off the printer. Do not attempt to diagnose thermistor wiring with power applied.
2. Check the thermistor connector on the xBuddy board. Open the electronics enclosure and locate the heatbed thermistor connector. Unplug it and firmly reseat it, ensuring it clicks fully into place.
3. Trace the thermistor cable for damage. Follow the cable from the bed underside to the electronics bay. Look for pinch points where the cable passes through routing channels, heat-related damage near the heated bed, or cuts from previous maintenance.
4. Measure thermistor resistance with a multimeter. With the connector unplugged, measure resistance across the two thermistor leads. At 20–25°C ambient, the reading should be approximately 85–110 kΩ. An open-circuit reading (infinite or “OL”) confirms the cable or bead is broken.
5. Replace the thermistor cable if the circuit is open. Install an NTC 100k heatbed thermistor and route it carefully, securing it with Kapton tape as in the original configuration.
6. Restart and verify. Power on and confirm the displayed bed temperature matches the actual room temperature before attempting to heat.

Parts Required

• Replacement NTC 100k heatbed thermistor cable (if open circuit is confirmed)
• Kapton tape (to re-secure thermistor bead)
• Digital multimeter

If the thermistor measures correctly but the error persists, contact Prusa Support at help.prusa3d.com — the xBuddy board’s thermistor input circuit may need evaluation.

Frequently asked questions

What does Prusa 13207 mean?

Prusa error 13207 (Bed Mintemp Error) appears on the MK4 and its equivalents are #31207 on the CORE One, #26207 on the MK4S, #27207 on the MK3.9S, #21207 on the MK3.9, #28207 on the MK3.5S, and #23207 on the MK3.5. The printer detected a bed thermistor reading below 5°C — a value so low it almost certainly indicates a disconnected or broken thermistor rather than the bed actually being that cold.

How do I fix Prusa 13207?

Prusa error 13207 means the bed thermistor read below 5°C. Learn how to diagnose a disconnected or broken thermistor and restore normal heating operation.