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Filament Runout

Bambu Lab 3D Printer

Severity: Moderate

Source: OnlyErrorCodes.com — Every error code. One place.

Bambu Lab Filament Runout Error — Fix Guide

What Does This Error Mean?

A Bambu Lab filament runout error pauses the print when the sensor detects that the spool has run empty or filament feeding has stopped. Load a new spool of the same filament type and colour, then tap Resume on the touchscreen or in Bambu Handy to continue the print from where it paused.

Affected Models

  • Bambu Lab X1C
  • Bambu Lab X1E
  • Bambu Lab P1S
  • Bambu Lab P1P
  • Bambu Lab A1
  • Bambu Lab A1 Mini

Common Causes

  • Filament spool has run out
  • Filament has snapped mid-spool due to brittleness (moisture-damaged filament)
  • Tangle on the spool preventing filament from feeding to the extruder
  • Runout sensor triggered falsely by a temporary feed resistance

How to Fix It

  1. Do not cancel the print. The printer is paused and will hold its position. Note the filament type and colour currently loaded.

  2. For AMS users: load a new spool of matching filament into the same AMS slot. The AMS will automatically feed the new filament and the printer will resume after a short purge.

    For best results, use the same brand and colour to avoid a visible seam line at the resume point.

  3. For external spool (non-AMS): remove the empty spool, load a new spool, and feed the filament into the extruder. Tap Load Filament on the touchscreen and wait for it to feed through, then tap Resume.

  4. If the runout was caused by a tangle rather than an empty spool, clear the tangle before resuming. Pull the filament back, free the tangle, and re-feed.

    Moisture-damaged filament becomes brittle and snaps easily, causing multiple false runout errors mid-print. Dry the filament in a food dehydrator or oven at 65°C for 4–6 hours before printing.

Frequently Asked Questions

Can I turn off the Bambu Lab runout sensor?

Yes — in Bambu Studio, open the printer settings and disable the filament runout detection under Filament Settings. Disabling it means the print will continue (and fail silently) if the spool runs out, rather than pausing. This is only useful if the sensor is giving false triggers — leave it on for normal printing.