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Creality K2 Plus Clogged Nozzle: Causes & Fixes

By Jules Carter
Last verified: · How we research

What our research found

  • Creality's FO2845 'extruder may be clogged' page lists six possible causes, and one of them is not a clog at all: a faulty CFS buffer can trigger the message falsely. Check this before you take the extruder apart a second time.
  • Creality's loading guide says the PTFE tubes behind the CFS on early K2 Plus units shipped at 40 cm and 50 cm, and that shortening them to 30 cm and 40 cm reduced feeding failures. Feeding resistance is a separate issue from clogs, but it produces similar symptoms.
  • In the one owner thread we read, a replacement nozzle and a replacement extruder motor did not stop repeat clogs. Owners pointed to a jammed cutter, a loose nozzle assembly and heat reaching the extruder gears, so 'keeps clogging' needs a different checklist from a one-off clog.

How we chose

  • Clearing steps follow Creality's own K2 Plus jammed-filament guide and its FO2845 error page.
  • Prevention tips come from Creality's K2 Plus filament-parameter and loading guides.
  • Owner explanations for repeat clogs are included only from a public thread we link to, and labeled as owner reports.
  • We left out electrical measurements and any step Creality does not document for owners.
On this page
  1. How we chose
  2. Symptoms
  3. Likely causes
  4. Fixes step by step
  5. When to replace parts
  6. Which models this applies to
  7. Is it a clog, or a false alarm?
  8. Prevention, according to Creality
  9. What owners report
  10. How we chose these steps
  11. Related guides
  12. Disclaimer
  13. Sources

Symptoms

  • The printer shows FO2845: "Extruder may be clogged", often during the flush stage of a CFS filament change.
  • Little or no filament comes out of the nozzle, or the extruder clicks.
  • Filament cannot be extracted even while holding the extruder clamp open.
  • A new nozzle clogs again within minutes of printing.

Likely causes

  • Filament stuck in the heat break of the integrated nozzle.
  • Filament jammed in the extruder gears, or gear debris and worn or broken gear teeth.
  • Damp, deformed or out-of-tolerance filament.
  • Slicer settings that do not match the filament actually loaded.
  • A spool that does not turn freely in the CFS.
  • A faulty CFS buffer causing a false clog message.
  • Owner-reported: a jammed filament cutter, a loose nozzle assembly, or heat softening filament at the extruder gears.

Fixes step by step

  1. Confirm it is a real clog — Creality's FO2845 page notes that a malfunctioning CFS buffer can show the clog prompt when nothing is clogged. Check that the buffer's blue indicator light is on, that the spool turns freely, and that the slicer profile matches the loaded filament.
  2. Open the extruder — Creality's guide removes the three screws on the extruder with a hex wrench, presses the compression block to separate the gears, and removes the extruder shell. Watch for the spring.
  3. If you can see filament in the heat break — Heat the nozzle to the filament's extrusion temperature and pull the deformed filament out with cutting pliers (Creality's Method One).
  4. If you cannot see filament in the heat break — Heat the nozzle to extrusion temperature, heat the tip of the cleaning needle, insert it into the heat break, wait about 30 seconds for it to cool, then pull it out slowly to bring the jammed filament with it (Creality's Method Two).
  5. Clean or clear the gears — Brush filament debris off the extruder gear and check it for damage. If filament is stuck in the gear itself, Creality's guide separates the gear assembly from the front cover and cuts the filament above and below the swollen section.
  6. Check the buffer — Creality's guide also covers filament jammed in the buffer: remove its fixing screws, pry the cover open gently along the middle gap, and cut out the swollen filament. Keep track of the spring and connectors.
  7. Replace the nozzle if it will not clear — Creality lists a severely clogged nozzle that is hard to clear as a reason to replace it. The K2 Plus uses an integrated heat break and nozzle; Creality's replacement guide unscrews it with a socket wrench at printing temperature and applies thermal grease to the new one.
  8. Re-run the self-check — After a nozzle swap, Creality's guide runs Input Shaping and Auto Leveling from the calibration menu before printing again.

When to replace parts

  • Replace the integrated nozzle when it is severely clogged and cannot be cleared, or when wear has reduced print quality (per Creality Wiki). K2 Plus nozzles fit only the K2 Plus.
  • Replace the extruder front cover if the extruder gear is damaged or deformed, as Creality's jammed-filament guide directs.
  • Contact Creality support if clogs return after the nozzle, gears and buffer have been checked.

Applies to: Creality CFS (Creality Filament System)

Research note: this guide is compiled from five Creality Wiki pages, a Creality blog post and one public thread on the Creality Community Forum. We do not test products ourselves; every step links to where it comes from. See how we research.

Which models this applies to

The step-by-step clearing method comes from Creality’s K2 Plus jammed-filament guide [1]. Creality republished the same procedure on its blog under the title “How to Fix Filament Jams on Creality K2 Series” (Creality blog [6]), and its FO2845 error page [2] lists the K2 Plus, Creality Hi, K2 Pro and K2 as applicable models. Parts differ between models, though: Creality says K2 Plus nozzles fit only the K2 Plus (nozzle guide [3]). If you own a K2, K2 Pro or K2 SE, check your model’s wiki section before ordering parts.

Is it a clog, or a false alarm?

Creality’s FO2845 page [2] says the prompt usually appears during the flush stage of a CFS filament change and lists these possible causes:

Cause on Creality’s list What to check
Filament issues (uneven diameter, moisture, deformation) Dry or swap the spool
Spool stuck or CFS shaft not turning smoothly Turn the spool by hand inside the CFS
Slicer parameters don’t match the filament Confirm the profile matches what is loaded
Damaged extruder gear (broken or worn teeth) Inspect the gear once the extruder is open
Filament stuck in the hot end Clear the heat break (steps above)
CFS buffer malfunction causing a false detection Check that the buffer’s blue light is on

The last row matters: if the buffer is at fault, taking the extruder apart will not help.

Prevention, according to Creality

  • Dry moisture-sensitive filament. Creality recommends drying filaments such as PETG, TPU, CR-Silk, CR-PLA Matte, ENDER FAST PLA and PA before use (K2 Plus filament parameters [4]).
  • Don’t feed TPU through the CFS. Creality says TPU tends to bend in the CFS tube and cause extrusion and retraction failures, and that TPU at 80A, 75A, 70A or softer is too soft for its printers and can be flattened by the extruder gear, clogging the nozzle (K2 Plus filament parameters [4]).
  • Avoid 0.2 mm nozzles for carbon-fiber filament. For PA-CF, PAHT-CF and PET-CF, Creality recommends a 0.6 mm nozzle first, then 0.4 mm (K2 Plus filament parameters [4]).
  • Keep the filament path short and smooth. Creality’s loading guide [5] warns against sharp bends in the PTFE tube and says early units shipped with 40 cm and 50 cm tubes behind the CFS. Creality found that 30 cm and 40 cm tubes reduce feeding failures.

What owners report

We read one thread on the official forum, K2 PLUS clug [7] (12 posts, April to May 2025). One thread is a small sample, so treat these as examples rather than proof:

  • The original poster replaced the nozzle and it clogged again within minutes. Creality support then sent a new extruder stepper motor, and the problem continued.
  • One owner said a jammed cutter can block filament.
  • Another owner asked whether the nozzle is tight in the hot end. They said loose screws stop heat from travelling along the nozzle and cause blocks, and they mentioned a CM2784 warning that the nozzle assembly can come loose.
  • One owner blamed heat from the extruder motor softening the filament at the gears, and reported no further clogs after blowing air onto the extruder. This is a home modification, not a Creality recommendation.
  • One owner warned against heating the nozzle above 300 °C unless the filament is normally printed that hot, because some filaments start to burn and make the clog worse. They also reported replacing a nozzle after roughly 500 hours of printing.

How we chose these steps

The clearing steps follow the order of Creality’s jammed-filament guide: open the extruder, clear the heat break, clean the gears, then check the buffer. We added the FO2845 false-alarm check at the start because Creality lists it as a possible cause. Owner explanations for repeat clogs are kept in their own section and labeled. We left out the voltage and continuity checks on Creality’s FO2845 page; that kind of electrical diagnosis is best done with Creality support.

Disclaimer

This page summarizes publicly available manufacturer documentation and owner reports. We did not perform these procedures on our own equipment. The nozzle, cleaning needle and hot end reach printing temperature during these steps, so take care to avoid burns. Disassembly can damage parts or affect your warranty; contact Creality support if you are unsure. Creality’s documentation and firmware change over time, so check the linked sources for the current version. Last verified: 2026-10-23.

Sources

Sources for this page

  1. [1] Official Troubleshooting for K2 Plus Jammed Filament | Creality Wiki — accessed
  2. [2] Official FO2845: Extruder may be clogged | Creality Wiki — accessed
  3. [3] Official Replace K2 Plus Nozzle | Creality Wiki — accessed
  4. [4] Official K2 Plus Recommended Filament Parameters | Creality Wiki — accessed
  5. [5] Official General Troubleshooting Steps for K2 Plus Filament Loading and Unloading | Creality Wiki — accessed
  6. [6] Official How to Fix Filament Jams on Creality K2 Series | Creality Blog — accessed
  7. [7] Community K2 PLUS clug | Creality Community Forum — accessed

Product sources

A. Creality CFS (Creality Filament System)

  1. [A1] Official Creality CFS: 16-Color Filament System with Auto Switch & Relay — accessed
  2. [A2] Official K2 3Dプリンター｜Creality (CFS specification table) — accessed
  3. [A3] Official Creality K2 SE Combo 3D Printer — accessed
  4. [A4] Official CFS Filament Compatibility | Creality Wiki — accessed
  5. [A5] Official How does CFS connect K2 Plus? | Creality Wiki — accessed
  6. [A6] Official CFS User Manual | Creality Wiki — accessed
  7. [A7] Official Creality K2 Plus & CFS Frequently Asked Questions You Should Know — accessed

How we research

About the author

Jules Carter

Covers 3D printer troubleshooting and error codes. Articles are compiled from official and publicly available sources, with every claim checked against the linked source.

How we research

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