Recently, my Ender 3D Pro has been unable to print any large models successfully with PLA as the filament starts to expand inside the Teflon tube, causing a clog after about an hour of printing. I am starting to suspect that the problem is heat creep.

  • This occurs with the two brands of PLA filament that I use (3D Fila and Voolt 3D).
  • The hotend that I am using is the one that comes with the printer, I don't know what it is made out of.

I have tried many things to patch this problem:

  • Try to unclog it with the needle
  • Replace nozzle (three times)
  • Check if the Teflon tube is touching the nozzle
  • Increase temperature from 200 to 220 °C
  • Increase temperature from 200 to 215 °C

If the problem is indeed heat creep, I have plans to control the heat sink temperature with a Peltier and an extra thermometer. Any other ideas are appreciated.

  • 1
    $\begingroup$ Is it B-grade rolls or good quality filament? I had bad filament appear to clog but it was hung in the extruder with a bulge. $\endgroup$
    – Trish
    Dec 20, 2021 at 6:13
  • $\begingroup$ PLA does not clog unless dirty. Something about your printer is seriously FUBAR. I would bet the problem is the extruder being worn out, dirty or incorrectly tightened and therefore not gripping the filament. Heat creep is certainly not the problem unless your fan is broken. $\endgroup$
    – AzulShiva
    Dec 27, 2021 at 19:44

2 Answers 2


Since you mentioned "Check if the Teflon tube is touching the nozzle", it sounds like you've disassembled the tube from the couplings and put it back together. This is error-prone and in my experience the main/only likely cause of clogging in Creality hotends. Heat creep is unlikely unless you're operating in a very high ambient temperature or have a failing/failed fan.

The tube can't just be "touching" the nozzle. It needs to be compressed against it. There are various ways to do this, but what usually worked best for me (before I moved to a different setup) was to back the coupler out of the heat sink by at least 1-2 full turns, press the tube all the way in against the nozzle, then tighten the coupler back down to compress the end of the tube against the nozzle mating surface.

The end of the tube also needs to be clean cut, straight, and undamaged. If it's charred, bent, gnarled, whatever, cut it straight with a razor blade while holding it in a jig to make sure the cut is perpendicular. You can find several such jigs (PTFE tube cutting tools) on Thingiverse or make your own or buy one. I like to also take the razor blade and chamfer the outside of the tube end ever so slightly before inserting it. I do this by hand, but I've seen videos of it being done with a jig that looks something like a pencil sharpener, which would probably be the best way.

  • $\begingroup$ Apparently, that was the problem. To solve it, I followed a hack from this video: link. Basically, the idea is to put a small piece of Teflon tube inside the hotend before attaching the other one. $\endgroup$ Dec 30, 2021 at 8:51

This sounds like heat creep may be the problem. For preventing heat creep to occur you should do the opposite, print at lower temperature, tweak retraction length and increase cooling of the cold end.

A Peltier element is not very effective cooler, use a bigger fan, or a fan with a higher flow rate. Note that the Peltier element required a large cooling body and a fan as well, so this adds a lot of weight to and limits space of the hotend. You should not go there, it has been tried before.


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