K1 SE suddenly heats to 240 °C during purge — slicer and filament temps ignored (CFS active, PETG & PLA tested)

Flagship K Series Creality K1 SE
1

Hi everyone,

I’m completely out of ideas at this point and would really appreciate some help or clarification from Creality or anyone who has experienced this issue.

My K1 SE suddenly started heating up to 240 °C during the purge phase, completely ignoring the temperature set in the slicer or filament profile.
This behavior appeared out of nowhere — I did not perform any firmware update or change anything major. It was working perfectly before.

Problem Summary

  • The printer preheats correctly to my slicer-defined temperature (for example 230 °C for PETG or 215 °C for PLA).

  • Right before the print starts, it jumps up to 240 °C during the purge phase, regardless of slicer or filament settings.

  • After the purge, it continues printing at the correct temperature again — but the purge overheats the filament and ruins first-layer adhesion.

Troubleshooting I’ve done

Creality Print

  • Tested official profiles (K1 SE 0.4 mm, K1 SE 0.6 mm) and my own edited version.

  • All of them heat to 240 °C during purge, even though the slicer and filament settings are correct.

  • Modified the Start G-code to use slicer variables (M104 S[...], M109 S[...]) — still ignored.

Filament Profiles

  • Created custom Geeetech PETG White (230 °C) and eSun PLA (215 °C).

  • Removed all filament-level start G-code — purge still runs at 240 °C.

  • Printer-side filament entry shows 190 – 240 °C, and it always uses the upper limit (240 °C).

Older Creality Print versions

  • Installed previous releases — same result, purge still at 240 °C.

Factory Reset

  • Performed a full factory reset twice and re-added Wi-Fi, materials, etc.

  • No change — issue persists.

Orca Slicer test

  • Orca connects fine over Moonraker (port 7125).

  • Prints perfectly at the correct slicer temperature.

  • However, CFS doesn’t load filament automatically, since Orca doesn’t call BOX_START_PRINT.

Observations

  • The purge temperature seems to come from somewhere inside the printer — possibly material_database.json — but I didn’t modify it.

  • Even after a factory reset, the printer still purges at 240 °C.

  • Other users on forums also mention similar behavior, but no one seems to know the exact cause.

Request for help

Could someone from Creality please confirm:

  1. Where does the purge temperature actually come from?

  2. Is it possible that the firmware or system has cached the wrong value?

  3. How can I force the printer to use the temperature defined in the slicer again?

I’ve spent many hours trying to fix this — testing different slicers, profiles, resets, even SSH into the system — but nothing changed.
Everything else on the printer works fine (CFS, leveling, prints), except this one frustrating issue.

Any ideas, explanations, or workarounds would be very much appreciated. :folded_hands:

Thanks in advance,
Roman

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