Clogged Nozzle
Restore filament flow when the nozzle is partially or completely blocked.
A clogged nozzle can cause under-extrusion, clicking from the extruder or complete loss of filament flow.
First, heat the nozzle to the normal printing temperature for the installed filament.
Try manually extruding a small amount of material.
If nothing comes out, check that filament is actually reaching the hot end and that the extruder gears are gripping it.
For a partial blockage, try increasing the nozzle temperature slightly and extruding fresh filament.
Many printers can also be cleared using a cold-pull technique. This involves heating the nozzle, inserting suitable filament, allowing the nozzle to cool partially and then pulling the filament out so debris is removed with it.
Follow your printer manufacturer's instructions because hot-end designs vary.
A nozzle-cleaning needle can sometimes clear debris, but take care not to damage the nozzle.
If cleaning fails, replacing the nozzle may be quicker and more reliable.
Always use the correct nozzle replacement procedure and tightening temperature specified by the manufacturer.
Common causes: degraded filament, dust, foreign particles, incorrect temperature, heat creep.