HomeBrandsBambu LabFDM 3D Printers0300_0400
B
0300_0400
Moderate
Bambu Lab · FDM 3D Printers
Bed Temperature Not Stable - Bed Thermal Fluctuation Outside Tolerance
Quick Answer
Error code 0300_0400 on your Bambu Lab FDM 3D Printers means: Bed Temperature Not Stable - Bed Thermal Fluctuation Outside Tolerance. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
A1A1 MiniP1PP1SX1 CarbonX1E
Likely Causes
  1. Printer placed on a surface that conducts heat away from the bed quickly (metal table, cold stone)
  2. Draft from AC or open window causing surface cooling
  3. Bed thermistor contact is degraded causing inaccurate readings
  4. Large print with high thermal mass absorbing heat faster than the bed can compensate
How to Fix It
1
Place the printer on an insulating surface like wood or a dedicated printer stand
2
Move the printer away from direct airflow sources (vents, fans, open windows)
3
Monitor the bed temperature in Bambu Studio and look for oscillation patterns
4
For large prints, consider preheating the bed for 5-10 minutes before starting the print
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
Thermal insulation pad for bed underside
Printer enclosure (for P1P or A1 models)
Related Error Codes
0300_01000300_02000300_03000500_01000500_0200
Video Guides
Loading video guides…
Search more on YouTube →