Error code 206 on the Elegoo Centauri Carbon 2 Combo indicates the chamber thermistor is electrically present but is reporting a temperature value outside the sensor’s valid operating range. Unlike error 205, which fires when the signal is entirely absent, error 206 fires when the motherboard receives a reading it cannot accept — typically caused by a degraded thermistor, a partially damaged cable, or a marginal motherboard port.

What the Error Means

The NTC100K chamber thermistor changes resistance with temperature, and the motherboard converts that resistance into a temperature reading. When the measured value falls below the minimum or above the maximum safe threshold, the firmware raises error 206 and halts to prevent running a print in an unmonitored chamber. Common triggers include a thermistor that has drifted out of spec due to age or heat stress, a cable with partial insulation damage that introduces noise into the signal, or a corroded connector creating intermittent resistance changes. At 25 °C the thermistor should read approximately 100 kΩ — values significantly above or below that point to a failed sensor.

Step-by-Step Fix

1. Power off the printer and unplug it. Allow all heated surfaces to reach room temperature before disassembly.
2. Remove the lid and bottom cover (ten M2 screws, 2.0 mm Allen key). Keep the screws organized — all ten are the same size.
3. Inspect the chamber thermistor cable along its full length for pinched spots, cracked insulation, or bent connector pins. Repair or replace the cable if visible damage is found.
4. Re-seat the thermistor cable firmly at both the thermistor body and the motherboard port.
5. With the cable unplugged from the motherboard, set a multimeter to the 200 kΩ range and measure resistance across the thermistor leads. A good thermistor reads approximately 100 kΩ at 25 °C. A reading substantially different from this value — especially one that drifts or fluctuates — confirms a failed thermistor.
6. Replace the chamber thermistor if the resistance test fails. Install the new thermistor, route the cable so it cannot be pinched by moving parts, and re-seat the connector.
7. If the new thermistor still produces error 206, the motherboard thermistor port may be out of calibration or faulty. Contact ELEGOO support for further diagnosis.

Parts Required

• NTC100K chamber thermistor (replacement unit)
• 2.0 mm Allen key
• Digital multimeter (200 kΩ range)

If the error continues after replacing the thermistor and verifying all connections, reach out to ELEGOO support with your resistance measurement results for additional assistance.

Frequently asked questions

What does Elegoo 206 mean?

Error code 206 on the Elegoo Centauri Carbon 2 Combo indicates the chamber thermistor is electrically present but is reporting a temperature value outside the sensor's valid operating range. Unlike error 205, which fires when the signal is entirely absent, error 206 fires when the motherboard receives a reading it cannot accept — typically caused by a degraded thermistor, a partially damaged cable, or a marginal motherboard port.

How do I fix Elegoo 206?

Error 206 on the Elegoo Centauri Carbon 2 Combo means the chamber thermistor is connected but returning an impossible temperature value. Inspect, test, and replace the thermistor to clear the fault.