Temperature spike

I recently started observing temperature spikes that cause the print(er)job to abort and the printer to shutdown.
This is the case both when [trying to] print pla and abs.
As a result printing has become impossible.
What can I do to make the extruder heat up more slowly and gradually, without spikes that stop the process?
Your help / info will be much appreciated.
W.P. Ginfo

Is the spike in the extruder or on the bed?

Do you mean that the extruder is overheating or that there are sudden drops and surges alternatively on your temperature curve?

Placement of the object completed OK

Slicing completed OK

Heating of bed 55C OK

Them the extruder kicks in by mving to 0,0,0 and switching ON
Subsequently there is a spike of the extruder [graph] down-up - down [all in one go] and the printing process is halted, the bed and extruder are automatically switched off.

I previously successfully printed with pla.

It appears there is a safety mechanism that kicks in.
How to slow things down enough to let the extruder heat up gradually…
Thnx for your help.


This sounds like a short or an open on the extruder thermistor.
Check the wires on the thermistor and make sure they are not shorting out on the heater block.
You should also check the soldering to make sure there is not a faulty soldering joint.

Could you post a picture of the graph?


thanks for your reply.
I think I’ve just found the answer…
I noticed the thermistor had -ever so sightly- moved from it’s hole in the heating block.
Now that I’ve moved it back into position, the spike has not completely vanished, but it no longer triggers a shutdown of the printing process.
Thnx all, for your help and suggestions.
W.P. Ginfo