Centauri Carbon 2: errors 101, 102, 103 or 104 (bed or print head not heating, or a thermistor fault)
Guide based on the manufacturer's official documentation; usi3d has not yet verified it on a machine.
Technology: FDM · Brand: Elegoo · Symptoms: The printer shows an error code or message, The hotend or the bed does not heat, Temperature error (MINTEMP, MAXTEMP, thermal runaway) · Updated on 10 October 2026
Symptom
The Centauri Carbon 2 stops with error 101 (check the heated bed and its wiring), 102 (heated bed temperature sensor disconnected), 103 (check the print head and its wiring) or 104 (nozzle temperature sensor disconnected), and the bed or the nozzle does not reach temperature.
Likely causes, from most to least likely
- 101: the bed thermistor, the mainboard, the power supply, the heated bed or its control board is damaged.
- 102: the bed temperature sensor cable is loose or damaged, or the heated bed or the mainboard is faulty.
- 103: the print head CAN bus cable makes poor contact or is damaged.
- 103: the ceramic heater cable is loose or damaged, the heater is cracked, or the tool head heating interface board is faulty.
- 104: the hotend thermistor cable is loose or the thermistor is damaged.
Checks to tell which one it is
- Note the exact error number: 101 and 102 concern the bed; 103 and 104, the print head.
- For 101, restart, let the bed cool for 10 to 20 minutes and check whether the screen shows it well below the room or nozzle temperature: if so, the bed thermistor is faulty.
- For 103, set the nozzle to about 200 °C and move the print head by hand without touching the nozzle: if the error appears or clears as it moves, the CAN bus cable makes poor contact.
Before you start
Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.
Step-by-step fix
Reconnect the bed sensor (102)
Switch off at the power switch, unplug and remove the lid. With the 2.0 mm Allen key, remove the ten bottom cover screws, reconnect the bed temperature sensor cable on the mainboard and check that the connector pins are straight. Plug in and switch on.
Check: Error 102 no longer appears.
If that does not fix it: Elegoo describes a cross-test with the chamber sensor cable to tell whether the bed or the mainboard is faulty; with that result, order the right spare part.
Check the bed thermistor (101)
Restart the printer and wait 10 to 20 minutes for the bed to cool. Compare the bed temperature on the screen with the room temperature or, without a thermometer, with the nozzle temperature.
Check: The bed reads roughly the same as the room and the nozzle.
If that does not fix it: If it reads clearly lower, the bed thermistor is damaged and must be replaced.
101: mainboard, power supply and bed board, only if you can work safely with electricity
Elegoo's checks are done with the bottom cover off and the printer plugged in, and the heated bed control board carries mains voltage: if you cannot measure live circuits safely, skip them. If you can: request bed heat from Control and see whether its light comes on on the mainboard; while it heats, measure whether the bed control board receives 24 V and what its AC input voltage is.
Check: You know what is faulty: no light, the mainboard; no stable 24 V, the power supply; your mains voltage at the input, the heated bed; none, its control board.
If that does not fix it: Order the right spare part from Elegoo; according to Elegoo, these checks do not void the warranty.
103 when moving the print head: the CAN bus
Set the nozzle to about 200 °C and, once there, move the print head by hand without touching the nozzle while watching the screen.
Check: If 103 appears or clears as you move it, the CAN bus makes poor contact: replace it.
If that does not fix it: If nothing changes, switch off, unplug and inspect the CAN bus cable (damaged sheath, loose connectors); if it is fine, check the heater (next step).
Check the ceramic heater and its connector (103)
With the printer off, unplugged and the nozzle cold, open the CANVAS top cover if fitted and the print head front cover, unplug the part cooling fan, loosen the nozzle assembly screws with the 2.5 mm key and take it out. Remove the silicone sock and the heater retaining ring, look for a cracked heater or damaged wires, then unplug and reconnect its connector.
Check: Once refitted and restarted, the nozzle reaches 200 °C without the error.
If that does not fix it: If the heater is cracked or its connector damaged, replace the heater assembly; if not, check whether the port of the tool head heating interface board is loose and reseat it.
Reconnect the hotend thermistor (104)
Switch off, unplug and remove the lid and the print head front cover. With the 2.5 mm key, loosen the hotend screws, take it out and reconnect the thermistor cable.
Check: At power-on, 104 no longer appears.
If that does not fix it: If it persists, the hotend thermistor is damaged and must be replaced.
Information for Elegoo support
If the error persists, write to Elegoo support with a video of how it appears, the serial number (on the white label next to the power switch) and what you saw: the bed temperature when cold, the mainboard light, the 24 V and the condition of the CAN bus and print head connectors.
Check: Support tells you which part to replace.
If that does not fix it: Follow their instructions.
Prevention
- Before opening the base or the print head, switch off at the power switch, unplug and let the nozzle and bed cool.
- Do not pull or over-bend the print head wiring when cleaning or replacing parts: poor CAN bus contact causes 103.
- Whenever you remove the hotend, firmly reseat the heater and thermistor connectors before closing up.
Still not fixed?
Tell usi3d's AI about your case: choose your printer, describe what you see and add photos if you like. It proposes checks step by step, with their sources.
Printers it applies to
Elegoo Centauri Carbon 2.
Official sources
This guide summarises the official documentation linked here:
This guide is general information: usi3d has summarised it from the official documentation linked here, and it may not match your model, its version or its firmware. If in doubt, follow the manual and the support of your printer's manufacturer. You decide what you do with your machine, and working on it may affect its warranty.