Prusa 3D Printer Error Code 8: How to Fix It

Q: Can I resume my print after a Prusa filament run-out error, or do I have to start over?

In most cases, yes — you can resume your print after fixing Error Code 8. Prusa printers are designed with filament run-out recovery in mind. The printer parks the print head, maintains nozzle temperature, and saves the print position so you can reload filament and continue from where it stopped. However, if the printer was left paused for a very long time and the print bed cooled significantly, the print may have detached from the bed and you may need to restart.

Q: Why does my Prusa keep showing Error Code 8 even though filament is loaded?

If your Prusa shows Error Code 8 with filament loaded, the most common causes are a dirty or faulty filament sensor, a partial nozzle clog causing inconsistent extrusion that the sensor interprets as run-out, or a filament tangle on the spool preventing smooth feeding. Clean the sensor with compressed air, check for tangles, and try performing a cold pull to clear any partial clogs. If the issue persists, test with the filament sensor temporarily disabled via the LCD settings menu.

Q: What filament types are compatible with Prusa printers to avoid future run-out issues?

Prusa printers support a wide range of 1.75mm filaments including PLA, PETG, ABS, ASA, TPU, and more depending on your specific model and hotend type. To minimize run-out and feeding issues, use quality filament with consistent diameter tolerances, store filament in airtight containers to prevent moisture absorption, and ensure spools are loaded in a way that allows free rotation without tangling.

Q: How do I disable the filament sensor on my Prusa printer?

To disable the filament sensor on most Prusa i3 MK3/MK3S/MK3S+ models, navigate to the LCD menu by going to Settings, then find the 'Fil. Sensor' option and toggle it to 'Off.' On Prusa Mini models, go to Settings > Filament Sensor and disable it there. Keep in mind that disabling the sensor means the printer will no longer automatically pause when filament runs out, so you will need to monitor your prints more closely.

Q: How can I prevent filament run-out errors from happening mid-print in the future?

The best way to prevent Error Code 8 is to weigh your filament spool before starting a long print and compare it to the estimated filament usage shown in your slicer software (such as PrusaSlicer). Make sure you have more than enough filament on the spool before starting. You can also use slicer settings to deliberately insert a filament change at a strategic layer height when you know a spool is getting low, allowing you to plan the swap in advance rather than being caught mid-print.

Abstract

Prusa Error Code 8 means your printer has detected that it has run out of filament mid-print. This is triggered by the filament sensor noticing that no material is feeding through the extruder, which pauses the print to prevent a failed job. The good news is this is a straightforward issue to resolve — you simply need to load a new spool of filament and resume printing from where the printer left off.