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Hotend wont heat past 170 C  

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Active Member
RE: Hotend wont heat past 170 C


Hi Zoltan, I did al calibrationg options successfully before, but I just finished another MBL after cheking under and above the plate for obstructions wich could affect it. No obstructions and again a successful test.

Posted : 14/10/2020 8:35 pm
Member Moderator
RE: Hotend wont heat past 170 C

Time to try print, let me know if succeeded

even an old man can learn new things 🙂
Standard I3 mk3s, MMU2S, Prusa Enclosure, Fusion 360, PrusaSlicer, Windows 10
PRUSA MINI+ Prusalink + Prusa Connect

Posted : 15/10/2020 6:30 am
Active Member
RE: Hotend wont heat past 170 C

Okay, thank you all for helping, yesterday I found out the true reason and Zoltan was partly right.

I got a tip from a support admin, that I should check the g-code for missing lines at first.
The lines were there, but now I tried different things  with them and changed the temp to 215 in those lines. It worked for the temp, but the bed leveling directly before the printing still did´t work. So I temporarily deleted the line that does the MBL test. The print- result showed that the bed wasn´t straight. It seemed straight, though. I turned the printer by 90 degrees and got it nearer to the edge of the table and there it worked. I found out, that the table (wooden Ikea type) is very uneven. The printer didn´t wabble or something but anyway I use another table now and it seems to be working.
Thank you all again for your time! I hope you other guys get your problems fixed, too. 
I uüloaded the Pic that Giuliano Dipoppa, the support admin sent me for you to keep trying this possibility or change the heating to 215° like I did. Maybe it´s also the bed level, though. Good luck!
Posted : 16/10/2020 2:19 pm
Member Moderator
RE: Hotend wont heat past 170 C


it is great, that  you can print. The information you sent on the picture is for me well known, but the others can surely learn.

Nevertheless, do not remove those MBL lines from your prints permanently. I would advise to eliminate the reson of failed MBL.

Check all screws of the printer basement if they are tightly fixed. 

Happy printing !!!

even an old man can learn new things 🙂
Standard I3 mk3s, MMU2S, Prusa Enclosure, Fusion 360, PrusaSlicer, Windows 10
PRUSA MINI+ Prusalink + Prusa Connect

Posted : 16/10/2020 4:33 pm
New Member

I just receive a mini yesterday and encountered this problem. I am in Mid-America and this is my second mini [also have a MK3s]- I gave my first mini to a young girl [8yo] and she is flying high already. I ran into this problem once with my first and cannot remember how I fixed it. I am working on first layer calibration [it worked the first couple times] and tried getting the temp up with heat preset but it also goes to 172 and then back down to 171 etc.

I have to leave for the day but would like an answer for tomorrow. Boot 1.1.0 and Version 4.3.4. I have not yet gotten to load firmware. This is a brilliant printer and this seems like an easy fix? I have not used my MK3 since I received my first Mini. Thanks Aaron / [email protected]

This post was modified 11 months ago by
Posted : 12/01/2023 7:03 pm
Veteran Member Moderator
RE: Hotend wont heat past 170 C

could it be the custom gcode, start gcode?

default profiles cause the printer to heat to 170C to reduce the chance of the nozzle dribbling, during mesh bed levelling, then the printer heats to print temperature and begins the print!

M104 S170 ; set extruder temp for bed leveling  (this is probably the line that is causing you trouble, it sets a low temperature to reduce filament dribble)
M140 S[first_layer_bed_temperature] ; set bed temp
M109 R170 ; wait for bed leveling temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
M204 T1250 ; set travel acceleration
G28 ; home all without mesh bed level
G29 ; mesh bed leveling
M204 T[machine_max_acceleration_travel] ; restore travel acceleration
M104 S[first_layer_temperature] ; set extruder temp (this is probably the line that  you didn't wait for! it restores the  print temp for the first layer)

You can probably comment out, or remove the first M104 line

M104 S170 ; set extruder temp for bed leveling
this should cause the printer to ignore the low temperature start.
I don't have a mini to test with.
regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 12/01/2023 10:53 pm
Active Member
RE: Hotend wont heat past 170 C


Posted by: @josiah

I waited 3 months to get my Prusa Mini in absolute anticipating. I was going to get a printer from the most respected 3d printing company in the world. Let me say, its been an absolute let down. 

The issue I currently have is my hot end. I had a failed print where the print lost adhesion to the bed and some filament got stuck to the heater block and hot end. I figured, no big deal, this has happened before just clean up and restart. I figured the first thing I would do would be to do a first layer calibration again. I start the process and wait, after about 5 minutes the hot end temp will not rise above 170C. I restart the printer and try again, same thing. I cleaned up the hot end, still no go. Turned the power off waited a few minutes, tried again, no go. 

How can a failed print cause the hot end to not heat up past 170C? I am flabbergasted. What is super frustrating is that I paid 2X as much as I paid for my Ender3 and am having 2X the problems with the Mini.

Please someone, enlighten me as to why my hot end will not longer heat up. I have had this printer for 2 days. 

My other issues that have frustrated me:

Prints that go to the front of the bed peel away during print.
Watchdog constantly killing prints for no apparent reason.
Second T nut in assembly does not properly align with holes on Z assembly.
Still no wifi support.

There are more but no need to pile on. Just want to be able to continue printing with my $400+ printer. 

Dear Friend, on your Mini there is a Settings option (looks like a gear on the display), click that. The first option is return, the second option is TEMPERATURE. Click that.. From here you can set your nozzle to the desired temperature. 170c is the temp for mesh leveling the hotbed, after it is done with that, go into Settings and adjust for your desired temp. Good Luck!

Posted : 20/05/2023 3:01 pm
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