The K1 is not extruding: the gear spins or clicks (jam in the extruder or hotend)

Symptom

On the K1, K1C or K1 Max no plastic comes out of the nozzle even though the extruder gear turns, sometimes with knocking or clicking. It often happens when switching material after printing ABS: the new filament will not go in.

Likely causes, from most to least likely

1. The filament is tangled on the spool or at the PTFE tube inlet at the back.
2. Filament is stuck in the front cover of the extruder kit, next to the gears.
3. The blue PTFE tube inside the hotend, below the extruder, is blocked or deformed: the filament comes out with a mushroom-shaped tip.
4. The nozzle or the hotend throat is clogged.
5. There is filament debris on the extruder gears, or a gear is worn or deformed.
6. The extruder motor or its connection is failing and the gears do not turn when loading.

Checks to tell which one it is

• Check behind the printer that the spool turns freely and the filament is not tangled.
• With the nozzle at the material's temperature, open the extruder, release the top PTFE tube and pull the filament firmly to see what the tip looks like.
• If the tip comes out with a mushroom or umbrella-shaped bulge, the hotend PTFE tube is damaged.
• Try automatic loading and watch the gears: if they do not turn, suspect the motor or its connection; if they turn with clicking and extrusion is uneven, suspect the nozzle or the gears.

Before you start

Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.

Step-by-step fix

1. Untangle the filament

   Check the spool and the PTFE tube inlet at the back and carefully untangle the filament before printing again.

   Check: The filament feeds smoothly and comes out of the nozzle again.

   If that does not fix it: Pull the filament out hot (next step).

2. Pull the filament out hot and check the tip

   On the control screen press «OFF» to release the motors. Remove the blue clip and gently pull the PTFE tube out of the top of the extruder. Heat the nozzle to the material's recommended temperature and, once it is stable, pull the filament out quickly and firmly.

   Check: The filament comes out whole and the tip has no bulge.

   If that does not fix it: If the tip is mushroom-shaped, replace the hotend PTFE tube. If you cannot pull the filament out, clear it from the extruder cover (step 4).

3. Push the debris out with the kit needle

   If the filament will not go back into the hotend, pull it out and, with the nozzle hot and the extruder open, push the debris in the channel downwards with the needle from the accessory kit. Withdraw it straight away so molten plastic does not stick to the throat or the gears, and repeat if needed.

   Check: The debris comes out of the nozzle and new filament goes in and extrudes.

   If that does not fix it: If the needle will not go through, the clog is in the hotend: follow Creality's hotend clog procedure or contact its support.

4. Clean the extruder front cover and gears

   With the nozzle hot, open the extruder, remove the PTFE tube and cut the filament. Remove the motor cover and the three screws holding the extruder kit and lift it without pulling the cable. Then set the nozzle to 0 °C. Remove the two front cover screws, take out the stuck filament (with pliers if needed) and brush the debris off the gears with a soft brush.

   Check: The gears are clean with no damaged teeth, and after reassembly automatic loading extrudes properly.

   If that does not fix it: If a gear is damaged or deformed, replace the extruder kit assembly.

5. If it happened after printing ABS: blue PTFE tube and heat sink

   After printing ABS, Creality describes three places where it jams: in front of the extruder kit, in the blue PTFE tube below the extruder and in the hotend throat. Remove the blue tube and clear the debris with an air gun or the nozzle cleaning tool. If the tube will not come out, there may be filament between the tube and the heat sink: the hotend kit and heat sink have to be removed to clean it.

   Check: The tube is clean and new filament reaches the nozzle.

   If that does not fix it: If you cannot clean the tube, ask Creality after-sales for a new one.

6. Check the extruder motor

   If the gears do not turn during automatic loading, switch off and unplug the printer and check that the extruder motor cable is firmly connected.

   Check: The gears turn when you start automatic loading.

   If that does not fix it: If they still do not turn, the motor or the connection board may be faulty: replace the extruder motor or contact Creality support.

Prevention

• Do not turn off the enclosure fan while printing.
• Use the official slicer profiles and do not overheat the bed: Creality advises not exceeding 50 °C for PLA or 70 °C for PETG, and not printing with the nozzle too cold.
• If you get repeated clogs, level the platform again: Creality includes it among the measures to prevent them.

Still not fixed?

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Printers it applies to

The Creality K1 family: K1, K1 Max, K1 SE and K1C.

Official sources

This guide summarises the official documentation linked here:

• Filament Feeding Issue/Clogging Issue (K1C) · Creality
• K1 Max Filament Feed Issue/Clog Handling Procedure · Creality
• Hotend clogging troubleshooting after printing ABS by K1 series machine · Creality