Jump to content

Floating temperature values cause overheating of hotend

Recommended Posts

Posted · Floating temperature values cause overheating of hotend

Hey Ultimaker community,

I've been printing with an Ultimaker original succesfully for quite some time, but a few days ago the following problem started happening:

During printing my temperature drops very slowly and the hotend switches on but temperature doesn't rise. After around 20 seconds the temperature jumps up by a huge amount, as you can see on the screenshot (sometimes even jumps above MaxTemp). Burned plastic also starts flowing out of the nozzle after the temperature jump.

The whole measuring system works perfectly when reading room temperature and when heating up.



I've searched the internet and did some troubleshooting but the problem still occurs:


  • Check whether thermocouple still works - Doesn't look damaged and gives good readings.
  • Check wiring to main board - Wiring between sensor and main board still working.
  • Check whether it is a software problem - Autotuned PID controller and used different slicers and controllers (Cura, Slic3r, Pronterface, RepetierHost)
  • Check external interference - there are some dimmers in the same circuit as the printer which could cause voltage peaks, but switching off all of those did not make a difference.
  • Check thermocouple amplifier board - Everything is properly connected, LED works and sensor gives good readings

This pretty much eliminates all hardware and most of the software causes. If the machine loses connection with the sensor the temperature would instantly jump to its maximum or minimum value right? (or is this filtered by the PID controller?).

My last guess would be that the problem lies in the firmware (I'm using The version of marlin that Cura installs, the display shows : 13.03 250000_single).

Do you have any tips/guesses?


  • Link to post
    Share on other sites

    Posted · Floating temperature values cause overheating of hotend

    This is very unlikely a firmware issue.

    It is a common problem to occur on Ultimakers that are several months to a few years old. The quick fix is to switch to the other temp cable. There are 2 cables - one for each nozzle (in case you get the dual nozzle upgrade). For now - just try the other cable (you have to switch both at the print head and also underneath the printer).

    UM doesn't properly crimp the wires in the cable at the connector and instead solders them. This is not good because the solder makes the cable stiffer and bending (during movement during printing) can cause these tiny strands to break - one at a time.

    Switching to the other cable should help for a few more months. Also make sure you do as good a strain relief as possible. When the second cable breaks you can replace them both.


  • Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
    • Our picks

      • S-Line Firmware 8.3.0 was released Nov. 20th on the "Latest" firmware branch.
        (Sorry, was out of office when this released)

        This update is for...
        All UltiMaker S series  
        New features
        Temperature status. During print preparation, the temperatures of the print cores and build plate will be shown on the display. This gives a better indication of the progress and remaining wait time. Save log files in paused state. It is now possible to save the printer's log files to USB if the currently active print job is paused. Previously, the Dump logs to USB option was only enabled if the printer was in idle state. Confirm print removal via Digital Factory. If the printer is connected to the Digital Factory, it is now possible to confirm the removal of a previous print job via the Digital Factory interface. This is useful in situations where the build plate is clear, but the operator forgot to select Confirm removal on the printer’s display. Visit this page for more information about this feature.
          • Like
        • 0 replies
      • Ultimaker Cura 5.6 stable released
        Cura now supports Method series printers!
        A year after the merger of Ultimaker and MakerBotQQ, we have unlocked the ability for users of our Method series printers to slice files using UltiMaker Cura. As of this release, users can find profiles for our Method and Method XL printers, as well as material profiles for ABS-R, ABS-CF, and RapidRinse. Meaning it’s now possible to use either Cura or the existing cloud-slicing software CloudPrint when printing with these printers or materials
        • 9 replies
    • Create New...