P
12211
Moderate
Prusa · FDM 3D Printers
MINTEMP Bed - Heated Bed Thermistor Reading Too Low
Quick Answer
Error code 12211 on your Prusa FDM 3D Printers means: MINTEMP Bed - Heated Bed Thermistor Reading Too Low. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
MINI+MK3.5MK3S+MK4MK4SXL
Likely Causes
  1. Bed thermistor cable damaged where it flexes during Y-axis movement
  2. Thermistor connector on the Buddy board came loose during shipping or maintenance
  3. Bed thermistor has failed open circuit
  4. Cable harness to the bed has a broken conductor in the textile sleeve
How to Fix It
1
Check the bed thermistor connector on the mainboard under the printer
2
Trace the bed cable harness for visible damage or pinch points
3
Measure bed thermistor resistance (should be ~100K at room temperature)
4
On MK3S+, check the cable where it passes through the textile sleeve near the rambo board
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Replacement bed thermistor with cable (Prusa OEM)
Replacement cable harness (model specific)
Related Error Codes
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