Hotend preheat error #26202 (MK4S) #13202 (MK4) # 27202 (MK…

What happened?

The printer is showing the message "Hotend preheat error: Check the print head heater and thermistor wiring for potential damage"

Error name: Hotend preheat error

Error code: #26202 (MK4S) #13202 (MK4) # 27202 (MK3.9S) #21202 (MK3.9) #31202 (CORE One)

This error is shown when the printer can't heat the nozzle more than 2 ºC for 20 seconds. The printer starts a safety feature that instantly stops the heating process and displays the message on the screen. The printer then waits for the user to inspect all parts and if needed fix the issue.

How to fix it?

Make sure that the ambient temperature where the printer is is stable, and above 10 ºC.

Extruder inspection

This error can be caused by any damage to the hotend heater or the hotend thermistor.

Access the LoveBoard and check the heater and thermistor cables. Make sure that they are connected correctly and that there is no damage along their length.

xBuddy board inspection

On the main board check if the fuse that protects the extruder is not damaged.

Make sure that the Loveboard main cable is correctly connected to the xBuddy board.

Multimeter check

If you have a multimeter available, use this guide to check the resistance on the hotend heater and the hotend thermistor.

11 comments

Kboruff

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2 months ago

I just completed my upgrade from 3s to mk4s.
I am getting this warning. I double checked and made sure the hotend thermistor wasn't plugged into the heartbreak spot. Tried again and the error continues. Attempting basic continuity tests for the hotend and thermistors didn't cause the piezo speaked in my innova to go off so something is strange.

Kboruff

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2 months ago

Turns out my heater cartridge arrived with a broken lead right above the heater block. Trying to get a replacement. The wires on my heater cartridge were also badly frayed.

Dan

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3 months ago

Same as some others here I go that error after installing a MMU3 on my MK4. During testing it was noted that the temperature was lowered by 20 Deg. C just prior filament change while printing on the tower. Afterwards the temperature order was back again to printing temperature, but the actual temperature raised too slow, leading to print on the object on temperatures well below target temperature. That gap between target and actual temperature was small at the beginning of the print, and became bigger with each filament change. At some point, it seems that this triggered the interruption of the print and to the error message. Wires of thermistor and heater were inspected without visual damages, plugs were properly fixed at the lovboard. Printing with one color only tested without issues and errors. I lowered the fan speed to max. 40% to prevent fast cooling during filament changes. Two test prints after that change with multi (5) color prints were done sucesfull. My conclusion would be an underperforming heating element or, on the software side there should be a hold point to wait for continue to print after filament change until actual temperature is within acceptable range. My MK4 was runnign for more than a year before installing the MMU3. Did not find information about the life time / performance of the heating elemnt in relation to running hours and heating cycles.For a one color print, heating times are not from an interest, so perofmrmance of the heater will be not an issue until the heater is dead.

kandlg90

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3 months ago

I received this error on the MK4S during filament changes after installing the MMU3. The first three attempts at a multi color print all failed. I had removed the sock and reinstalled it and that fixed the problem.

Echo

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3 months ago

Any fix for this yet? Only happens to me on multicolour prints and not always at the same colour change. Single colour prints work fine. I'm sure Prusa will fix this at some point but at the moment there's not a lot of information.

Miro J.

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5 months ago

I have MMU3 and MK4s this hsppen on the colour change only. No issue printing with one colour.

Atlas Iverson

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5 months ago

I am having the same issue with my MK4. It only happens when I use Prusament PLA Galaxy Black. Prints fine with InputShaper or plastics other than Prusament. Wiring is fine. Room Temp is 294K. Although, the displayed heat on the LCD jumps, sometimes up to 10 degrees C. Bad sensors?

Atlas Iverson

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5 months ago

I have done over 300 tool changes since my last comment. I can confirm my problem only happens when I am swapping to Prusament PLA Galaxy Balck, it happens about half the time. Sometimes it happens on the first layer, sometimes an hour into a print, sometimes never; but always with Prusament PLA Galaxy Black. I can watch the temperature drop as the filament is loaded (or senors read false information). Turning the Cooling fan of makes a huge difference and almost triples the print time but it still cannot handle Prusament PLA Galaxy Black.
Any solutions?