P
12202
Moderate
Prusa · FDM 3D Printers
MAXTEMP Hotend - Temperature Exceeds Maximum Safe Value
Quick Answer
Error code 12202 on your Prusa FDM 3D Printers means: MAXTEMP Hotend - Temperature Exceeds Maximum Safe Value. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
MINI+MK3.5MK3S+MK4MK4SXL
Likely Causes
  1. Thermistor short circuit causing falsely high temperature reading
  2. Heater cartridge wires touching thermistor wires in the hotend assembly
  3. Damaged thermistor reporting near-zero resistance
  4. Incorrect thermistor type configured after firmware flash
How to Fix It
1
Power off immediately and let the hotend cool to room temperature
2
Inspect hotend wiring for any crossed or bare wires between heater and thermistor circuits
3
Measure thermistor resistance; a short-circuited thermistor reads near 0 ohms at room temperature
4
Re-flash the latest Prusa firmware to restore default thermistor configuration
5
On MK4/MK4S, inspect the Nextruder PCB for solder bridges or damage
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 hotend thermistor
Nextruder heater block assembly (MK4/MK4S)
Thermal paste for thermistor seating
Related Error Codes
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