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3D Print Troubleshooting, Calibration & Parts

Prusa Error 13205: Heatbed MAXTEMP, Usually a Shorted Sensor

By LayerWalkerUpdated September 24, 20263 min read
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Prusa Error 13205 — MAXTEMP ERROR — heatbed read above range
Short answer

Prusa error 13205 means the heatbed thermistor reported a temperature above its valid range. A genuinely overheating bed is rare; a shorted or pinched sensor wire reads maximum instantly and produces exactly this. Prusa’s text says to check the heatbed thermistor wiring for damage, and that is where to start.

Sensor faults fail in two directions and the direction is diagnostic. A short circuit reads at the top of the range and gives MAXTEMP. An open circuit reads at the bottom and gives MINTEMP. Knowing which one you have narrows the fault before you touch anything.

How the firmware sees each kind of sensor fault. The direction of the error tells you the kind of wiring problem.
How the firmware sees each kind of sensor fault. The direction of the error tells you the kind of wiring problem.

Where to buy

Check in this order

  1. Pinched or crushed cable. Follow the bed loom through its full travel. Anywhere the cable passes a frame edge or a cable tie is a candidate.
  2. Connector contamination. Moisture, flux residue or a whisker of stray wire bridging two pins reads as a short to the board.
  3. Was the bed actually hot? Once it is cool and safe, feel it. If it genuinely was very hot, the fault is on the driving side — a MOSFET stuck on — and that is a board-level repair.
  4. Thermistor type in firmware. After a firmware change or a bed swap, the wrong sensor type produces nonsense readings across the whole range.

Why this is rarely an overheating bed

The heatbed is driven through a MOSFET that the firmware controls. For the bed to genuinely exceed its maximum, that MOSFET has to fail in the conducting state, which is uncommon. A cable pinched during assembly or a later maintenance job is far more likely, which is why the wiring check comes first.

Related codes

13201 is the bed failing to preheat, which is the opposite symptom. 13211 is the heatbreak sensor reading below range. 13213 is the control board itself overheating. On other models this same error reads 12205 (MINI), 31205 (CORE One), 35205 (CORE One L) or 23205 (MK3.5). Bed temperatures by material are in this reference.

Prusa Error 13205 FAQ

Is my heatbed actually overheating?

Usually not. A shorted thermistor wire produces the same reading instantly. Check the bed by hand once it is cool — if it was never hot, the sensor is the fault.

What is the difference between MAXTEMP and MINTEMP?

MAXTEMP means the sensor read above range, typically a short circuit. MINTEMP means below range, typically an open circuit. The direction identifies the wiring fault.

Can a firmware update cause 13205?

It can, if the thermistor type is set wrong afterwards or if you changed the bed without updating the setting. Worth checking if the error appeared straight after an update.

Do I need to replace the heatbed?

Almost never for this error. Cabling and connectors account for the overwhelming majority of MAXTEMP faults.

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