Material extruding out of top of the hotend V3


I have simply opened a new Topic, because I have not found my concern here yet.

My printer is relatively new, I have printed 140 hours so far, first hotent, first nozzle

My problem: a few days ago melted plastic started to squeeze out material at the top of the hot end. I disassembled the hotend and noticed that the mounting plate that fixes the extruder pipe to the heating block is slightly curved, leading to a gap where Material can escape. Where can this come from?

I cleaned the hotend and the nozzle in acetone and removed all residues, but there is still material leaking from the upper end of the hot end, which burns after a short time and creates an unpleasant smell.


Hi, so this was the first time you had removed the hotend from the block, right? This could be a manufacturing defect. Please, fill in the support form, attach a purchase invoice and a picture of the count of hours.


Hi Karolina,

thank you very much for your fast response. Yes, this was the first time I removed the hotend from the printer and the hotend from the heaterblock.

I only printed Z-ULTRAT and Z-ASA so far and never had the need to do any maintenance on the hotend/ the nozzle, besides from cleaning the nozzle.

I will fill a support file, thank you very much!



Hi Claudio,

We have got your support form, thank you for your understanding :slight_smile:


Hi this has happened to me 3 or four times. I have bought 5 hotends since buying my m200…


Hi, me to after 300h of printing:(



I have the same trouble all the time after I change my nozzle when they are clogg…
Even if I fellow the Zortrax procedure to change the nozzle, when the hot end is hot!!!
So have you got a good tricks to do it well because it cost a lot at the end !!!
Look at the last one, only 10 hours printing after I changed the nozzle…




Can you pass the picture once again? Sadly, I am unable to open the link you provided. Also, what material are you printing with?

Best regards,


Hi Karolina,

here is the picture.


By the way, I am printing here z-petg, but it also happen with z-asa or z-ultra…



Thank you for the photo. Did you change just the nozzle or the whole hotend? Despite the fact the nozzle is new - the material may still come out of the top of the worn-out hotend. Also, make sure the heater&thermocouple is firmly plugged into the PCB and that screws securing it in the hotend are tight.

Best regards,


Sorry to interfere now, but I might be able to contribute something to the solution of the problem:

As I understand, the hotend ist constructed in such a way, that you screw the nozzle with its thread into the aluminium block from the bottom At the top of the hotend, two screws are used to attach a metal tube to the aluminum block, into which the filament is inserted by the stepper motor and in which it begins to melt.

In the “normal” or not-leaking state, a circular tongue at the end of the metal tube comes into direct contact with a circular groove in the nozzle when it is screwed in.This is how the seal is achieved.
If this seal between the the metal tube and the nozzle is not tight, there will be an extrusion of molten material at the top of the hotend, or from below, above the nozzle.

Have you screwed the nozzle tight enough into the hot aluminium block of the hot end? You might need to apply a lot of torque (Caution, support the aluminium block to not damage the hotend!)

If this does not help, try to disassemble the hot end into its individual parts (nozzle, aluminium block and metal pipe from above) and then put the parts in acetone for two days. Then try to scrape off the residue of the molten and burned plastic inside the hotend, and the end of the metal tube, that faces the nozzle and from the threaded end of the nozzle.

Maybe the metal pipe has been pushed too far up in your case. The metal sheet, that holds the metal pipe in the aluminium block would then be bent as in my case. Try to bend the metal sheet straight again, so that the metal pipe reaches a little bit further inside the aluminum block.
Hopefully, the groove comes back into contact with the tongue, and thus the connection is sealed again.

@Zortrax: Maybe this problem could be solved by a more rigid connection between metal tube and aluminium block, or another type of Seal between metal tube and nozzle.


Thank you, Copterpilot,

It’s exactly as I suspected. But in all my cases, I tried to screw more or less hard. The first time I screwed tight, but the material went over anyway. Then, with another Hotend, I tightened the screw tighter, but I broke the metal tube above the Hotend, and another time I broke the thread of the aluminium part.
Anyway, I find all this is not very practical and would deserve clearer explanations from Zortrax .
Also, I also have a M300 with a Hotend V2, and I only very rarely have this problem, I only have these problems with the Hotend V3 of my 200+…

In any case I will try to follow your Copterpilot advice which seems to me very relevant. In the meantime, since 1 year and a half that I’ve had my m200+, I’ve had to replace the Hotend about ten times, which is expensive, compared to my M300 that I’ve had for 3 years, and for which I’ve only replaced it 7 times…