I have a serious heated bed issue with my Creality K2 Pro.
During a print, the bed target temperature was set to 110°C, but the actual temperature continued rising far above the target.
The printer log shows:
10:21:08 — 134.18°C
10:21:12 — 138.8°C actual / 110.0°C target
10:21:13 — 140.3°C actual
10:21:17 — 145.0°C actual
10:21:21 — 149.7°C actual
10:21:25 — 154.6°C actual
10:21:38 — 168.59°C
10:21:40 — approximately 171.07°C
During this process, I noticed visible smoke or vapor inside the printer enclosure. As soon as I saw it, I stopped the print immediately.
At that moment, I did not yet realize that the heated bed was overheating. Only a short while after stopping the print did I think to check the bed temperature and noticed that it had gone far above the 110°C target.
After this incident, the heated bed stopped heating completely. The printer still powers on and the bed temperature sensor shows approximately room temperature, but the bed no longer heats.
The printer now reports:
Error 2565 / key565:
“Heater heater_bed not heating at expected rate”
What is especially concerning is that the firmware clearly showed a 110°C target while the measured bed temperature continued rising far above it.
I have not opened or modified the printer and have stopped using it.
Has anyone experienced a similar issue on a K2, K2 Pro, or K2 Plus? Could this be a heated bed control board or power switching failure?
Do a test with a lower bedtemperature, for instance 50 degrees… if it goes beyond 65 you know you have a serious issue and need to find out why!
In the past there were issues with the firmware not detecting thermal runaways, resulting in fires… but that was a long time ago when Creality produced the Ender 3 Pro’s with Marlin firmware…
I think there’s something very wrong with your print.cfg (heated bed maximum temperature and PID) or a faulty bed AC module.
I’d advise you to replace the bed with a Ram3N bed and replace the bed switching module. The bed is absolutely no longer safe once it reaches those temperatures, and I no longer trust the bed AC module. The Ram3N bed is far better. So if you need to replace the bed, I would advise you to replace it straight away with a better one.
The dealer sent me a new bed and the bed control board.
They haven’t arrived yet, so I haven’t had a chance to test the printer.
When I got the warranty claim decision, I took apart the old bed and the thermal fuse had blown. I connected the bed to test it without the fuse (I just connected the fuse wires together) and it worked perfectly. However, I plan to replace the new bed and the control board as soon as they arrive. I also plan to revert to the previous firmware, which worked without any problems.
What is most surprising about this is that the printer logs confirm that the requested bed temperature was 110°C. In the Klippy log,the printer reported:
heater_bed: target=110 temp=135.9 pwm=0.000
This is particularly concerning because Klipper was already commanding zero heating power (pwm=0.000), while the heated bed temperature was 135.9°C and temp still continued to rise.
According to the other printer log, the bed later reached approximately 171°C while the target remained 110°C.
I received a new heated bed and heated bed control board under warranty. I replaced them, downgraded the firmware back to version 1.1.4.1, and now the printer is working normally again.