Bambu Lab 3D Printer Error Code 0300_0100: How to Fix It

Q: What does error code 0300_0100 mean on a Bambu Lab printer?

Error code 0300_0100 on a Bambu Lab 3D printer means the heatbed thermistor circuit is open. This tells the printer it cannot detect a valid temperature reading from the heated bed, either because the thermistor wire is disconnected, broken, or the thermistor component itself has failed. As a safety measure, the printer stops operation to prevent uncontrolled heating.

Q: Can I still print with Bambu Lab error 0300_0100?

No. When error 0300_0100 is active, the Bambu Lab printer will not allow printing because it cannot safely monitor or control the heatbed temperature. Attempting to bypass this would be dangerous, as thermal runaway — where the bed heats without limit — could cause a fire. You must resolve the thermistor fault before printing can resume.

Q: How do I know if my Bambu Lab heatbed thermistor needs to be replaced?

The most reliable way is to test the thermistor with a multimeter set to measure resistance (Ohms). Disconnect the thermistor connector from the mainboard and measure resistance across the two thermistor wires. At room temperature, a healthy thermistor will show a specific resistance value (typically in the range of 10kΩ to 100kΩ depending on the thermistor type). If your meter reads 'OL', infinite, or zero resistance, the thermistor is faulty and needs replacement.

Q: Will this error clear on its own after reconnecting the cable?

Yes, if the root cause was simply a loose or partially disconnected thermistor connector, re-seating the connector firmly, powering the printer back on, and running a normal startup sequence should clear error 0300_0100 automatically. The error is triggered in real time based on the thermistor circuit status. If it returns after reconnecting, the thermistor itself or its wiring is damaged and needs replacement.

Q: Is error 0300_0100 covered under the Bambu Lab warranty?

Component failures like a defective heatbed thermistor are generally covered under the Bambu Lab standard warranty (typically 12 months from purchase) if the failure is due to a manufacturing defect and not user damage. Contact Bambu Lab Support through their official portal with your printer's serial number and a description of the error. They may ship a replacement part or provide a return authorization. Avoid performing major disassembly before contacting support if your printer is still within the warranty period.

Abstract

Bambu Lab error code 0300_0100 indicates that the heatbed thermistor has an open circuit — meaning the printer cannot read the bed temperature because the thermistor wire is disconnected, broken, or has failed entirely. Without a reliable bed temperature reading, the printer will refuse to heat the bed or start a print as a safety measure. This is a medium-severity issue that is often caused by a loose connector or damaged wiring, and in many cases can be resolved without replacing any parts.