Heater extruder not heating at expected rate | Ender 3 S1 Pro

Basic Information:

Printer Model: Ender 3 S1 Pro
MCU / Printerboard: STM32F401

Describe your issue:

Printer crashes suddenly after printing for x amount of time raising a error message saying the following;

Heater extruder not heating at expected rate
Transition to shutdown state: Heater extruder not heating at expected rate
See the ‘verify_heater’ section in docs/Config_Reference.md
for the parameters that control this check.

I do not know why this is happening… some models are printed 100%, other models are halted at a random height? I’ve already cleaned the nozzle, tried a pid tune and even let the printer stay at 210 degrees for multiple hours to see if the error happens again. For some reason the error happens very inconsistent and I hate it to pop up after a multiple hour long print… does anyone have any clue as to why this is happening?

P.S. I did see this post. Could this be the problem? Can I debug this in any easy way?

I would really appreciate if anyone could help me solve this issue! :crossed_fingers:
Thanks in advance!

– Tjeu

klippy.log (7.5 MB)

It certainly looks like a hardware problem, either the thermister or heater catridge, or the associated wiring. The printer was able to hold 210C for ages, and do it easily, and then all of a sudden, the temp starts to drop sharply (and it bounces around). The fact that it dropped so fast indicates to me that it is the thermistor that is faulty, if it was the heater cartridge you would expect the temperature to drop more gradually. So, I would start by replacing the thermistor, they are cheap and easy to replace.


Alright, thank you for the quick reply! I’ll check if I can buy one nearby and will update this post with the status after the replacement. :slight_smile:

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I replaced the thermistor and heater cartridge both (they were sold in a kit). After a 4+ hour print I didn’t get any error again, so it seems like the issue has been resolved!! Thank you very much for guiding me in the right direction :smile:


Glad that you got it going :slight_smile:

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