Heater extruder not heating at expected rate | replaced heater cartridge

Basic Information:

Printer Model: Ender 3 V2
MCU / Printer board: Version 4.2.7

klippy.log (992.9 KB)

I cut down the klippy file to fit max attachment size

Describe your issue:

Hi, I have this type of failure on a hemera volcano setup on ender 3 v2. I print PLA, but needed to print ABS for voron parts. I had moved the printer to my garage, added a new PID tune for 247c nozzle, 100c for bed and started printing. My print is for long periods of 12-20 hours. The printer fails with around 8 to 10 hour mark.

“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 use a standard e3d 24v 40W heater cartridge, after checking my klippy.txt file I noticed my heater extruder temp was slowly dipping with PID set high. I replaced it with the same heater cartridge I had in spare and same fault would pop up. I think I should try replacing the thermistor if not the control board. Pls help.

The temperature sometimes falls about 50°C within a second.
You may check all the wiring of the thermistor.
Also take care, that the printer gets not too cold in the night.

Make sure parts cooling is not blowing on the nozzle or heater block. If the parts cooling fan is on when you get this failure, do a PID tune with this fan running at the same percentage.

This is not a fan / PID issue.
As @EddyMI3D pointed out:

There is a sudden drop from 247°C to 205°C. This points to a broken thermistor, i.e. either the thermistor itself or the wiring.


I made sure that the print is not using the cooling fan, checked on in middle of print, and fan was still off.

The garage kept pretty warm at night, not much difference between day. But i can leave a thermistor in the garage to get a temp log of it. I currently ordered new heater cart and thermistor. I will update after install

Good catch! I belive so too now, noticed when i saw the printer after it had faulted. It burned the plastic where it was touching the nozzle. I belive maybe thermistor failed caused the PID and heater block to keep on heating past 247c, untill thermal runaway kicked in after??

Hi All,

I’ve replaced the temp probe as-well as the heater cartridge bought from e3d, both standard cartridges. I haven’t replaced the whole wiring going back to the control board. The extruder temp seems to be wobbling higher or lower multiple times before actually failing. The heater block is a volcano that has a silicone cover with it, confused with what maybe the issue, I am thinking of doing new connection from the control board to the cartridges.

I heard that powering a dc power supply without a ground might cause it to output unequal voltages. So I made sure that I am using an extension cable that has a solid ground for it. I don’t know what are really the next steps after the cables.

I attached the new Klippy text that shows this behavior.

klippy2.txt (4.7 MB)

I have been working on it for a bit and I believe that the printer is happy now and doesn’t seem to randomly stop. I did a bunch of things and don’t know which specifically was the fix.

I took apart my hot end, cleaned all the metal as I noticed some plastic made its way up there. I made sure that the heat block channel for the heater is smooth and clean, and make sure both thermistor and heater cartridge are in tight. I upgraded the heater cartridge wattage from 30W to 40W, then replaced the cabling that went back to the controller. This should have covered a wide range of issues so I decided to perform them all at the same time.

I replaced the cable because its been through allot of uses and bends, generally seemed like a good idea. I was a bit suspicious about the heater block being loose or not making much contact with the cartridge and fluctuating the temperature especially when its colder outside. But I still don’t have a solid answer to what was causing the weird fluctuations. Its passed a 16 hour print recently and I will update if any changes or solutions occur.

With the heater upgrade you really should redo your PID tune on that heater.