No filament comes out even though the extruder is moving, or extrusion is severely reduced and inconsistent. The extruder may be clicking. If you can hear the drive gear skipping, you have back-pressure — something is blocking flow through the hotend.
Partial vs. Full Clog
Partial clog: Some filament comes through but less than expected. Lines are thinner than normal, top surfaces have gaps, and the extruder may click occasionally but not constantly. This is the most common type.
Full clog: No filament emerges at all even at elevated temperature. The nozzle orifice is completely blocked, or filament has jammed solid in the heatbreak.
Cold Pull First — Before Anything Else
Heat to print temperature. Push filament through by hand until it flows cleanly. Set temperature to 90°C for PLA (100°C for PETG, 110°C for ABS). When it reaches that temperature, pull the filament out with firm, steady pressure — no jerking. The tip that comes out should have a perfect mold of the nozzle interior. If it’s discolored, textured, or brings out debris, the nozzle had contamination.
Repeat 2–3 times. This clears most partial clogs and some full ones. It’s faster and safer than any other method.
If Cold Pull Doesn’t Clear It
Try a higher purge temperature. Heat to the absolute maximum the hotend can reach safely. For V6 / Volcano hotends this is typically 280–285°C. Push filament through manually for 20–30 seconds. The increased temperature often liquefies carbonized material that won’t come out at normal print temperature.
Use a nozzle cleaning needle. With the nozzle hot, insert a 0.3–0.35mm wire (acupuncture needle or cleaning kit needle) into the orifice and move it in and out. This breaks up hardened deposits. Don’t force it.
Replace the nozzle. Brass nozzles are consumables. If a nozzle has been used for abrasive materials, or has been clogged with carbonized filament multiple times, replacement is faster than further cleaning. 0.4mm brass nozzles cost under $1 each in bulk.
Why It Keeps Clogging
Heat creep: The hotend cooling fan is failing or inadequate, so the heat zone extends upward into the cold zone and softens filament before it reaches the melt zone. The filament swells, jams, and the printer appears clogged. Check that the hotend fan runs continuously whenever the printer is powered (not just when printing). Replace if it’s slow or noisy.
Retraction too long: Retractions pull hot filament up into the cold zone. Direct drive: maximum 1.5mm. Bowden: maximum 5mm. Longer than these values causes repeated heat-zone jams that look like clogging.
Material switching without purging: Leaving PLA residue in a nozzle that then prints ABS at 240°C carbonizes the PLA. Purge with at least 100–150mm of new filament when switching between materials with different print temperatures.
Abrasive filament through a brass nozzle: PLA-CF, PETG-CF, and glow-in-the-dark filaments wear brass quickly. A worn nozzle with a rough interior traps material. Switch to hardened steel when using any filled or composite filament.