<p>Sounds like a thermostat problem, 60 degrees shouldn't be melting the first layers with PLA.</p>
<p>I would try manually checking the temperatures and move forwards from whatever results I got from that.</p>
<p>If the heats were fine, then I'd be inclined to return it as a faulty unit if it's under warranty.</p>

CC BY-SA 4.0
2022-05-12T11:21:56.510Z
I have changed the thermistor multiple times and definetly not. Im thinking its a G-code issue.
MJH12
CC BY-SA 4.0
2022-05-12T13:35:02.477Z
How could it be gcode? The gcode just sets the temperature right at the start if you're not doing fancy modifications to it. Have you tried flashing the firmware? I was going to suggest that but unsure what it would do to the warranty status
Kilisi
CC BY-SA 4.0
2022-05-12T14:02:33.050Z
I bought this unopened from a third party. I have not flashed the firmware. I will look into that. I have printed 4 10+ hour prints all beautifully since I started this thread. All at 200/60. so strange that changing the temp down 5 degrees on bed drops the hotend. What do you think about it being a fan issue? Maybe all both bed and hotend fans are firing at the same time?
MJH12
CC BY-SA 4.0
2022-05-12T14:08:19.733Z
I don't know sorry, but the firmware controls the fans. I have never had a fan issue so have no experience with that. The fact that the issue is intermittent could be a capacitor issue, but thats a board problem. If your board is playing up then you need professional help unless you're an electrician
Kilisi
CC BY-SA 4.0
2022-05-13T08:05:52.227Z
I still think there is something wrong with your heat readings, I have done 2, 3 and 4 day prints that don't have any melting bottom layers at 60 degrees bed
Kilisi
CC BY-SA 4.0
2022-05-13T10:38:56.347Z
Theres really no melting at all. I think im being a perfectionist.
MJH12
CC BY-SA 4.0
2022-05-13T11:08:07.330Z
Nothing wrong with that at all... good luck printing
Kilisi
CC BY-SA 4.0
2022-05-11T03:32:47.917Z
2022-05-11T03:32:47.917Z
Kilisi
<p>Could be a bad thermistor, could just need a pid tune. I would start with pid tuning it, if that doesn’t work I would swap it for a new one. Don’t forget to pid tune the new one if you end up going that route.</p>

CC BY-SA 4.0
2023-09-06T16:06:02.843Z
The OP states that they have *already* changed the thermistor (multiple times) in [this comment](https://3dprinting.stackexchange.com/questions/19368/changing-the-temp-from-200-60-in-any-degree-triggers-thermal-runaway/21404#comment37044_19370)
Greenonline
CC BY-SA 4.0
2023-09-06T15:07:25.033Z
2023-09-06T15:07:25.033Z
durbanpoisonpew
<p>I am new to 3D printing and having a strange issue I don't understand and would love some help with. I have an Ender 3 Pro and when I use the settings 200 °C &amp; 60 °C it prints fine. However, I want to change the bed to 55 °C as the bottom layers are melting a bit. I changed this in Cura to 200 °C &amp; 55 °C and get a thermal runaway after 20 minutes or so. I hit resume and the same thing after about 20 minutes, however, the times vary.</p>
<p>I did a PID using the same set temps 200 °C &amp; 55 °C and still thermal runaway. So I changed all the numbers back to 200 °C &amp; 60 °C and ran a PID on this original temps and ran perfect (except for the first layers melting a bit)</p>
<p>The odd part is the bed temp holds fine when adjusted to 55 °C, it's the hot end that starts to drop a few degrees (5 degrees) which triggers the runaway. Is this a fan issue (currently at 100%)? Before I started changing things I wanted to ask here.</p>
<p>Looking forward to your feedback. BTW I am able to change the PID right on the machine and have no experience altering G-code or the knowledge but am willing to try?</p>

CC BY-SA 4.0
2022-05-10T19:23:01.600Z
I assume you're getting a thermal runaway error.  Is there any evidence of the printer actually starting into thermal runaway?
Perry Webb
CC BY-SA 4.0
2022-05-10T19:25:36.280Z
Also what is the model of your 3D printer?  Your temperatures sound like you're printing PLA.
Perry Webb
CC BY-SA 4.0
2022-05-11T00:01:45.330Z
yes running hatchbox pla black. ender 3 pro  is all i know. Yes its a thermal runaway. I have been watching it and seeing the hot end temp drop.
MJH12
CC BY-SA 4.0
2022-05-11T22:13:33.730Z
i thought a thermal runaway was when things get way too hot?
dandavis
CC BY-SA 4.0
2024-02-03T19:12:47.850Z
The bottom layers experience elephant's foot, not melting. PLA only melts at ~180 °C
Trish
CC BY-SA 4.0
2024-07-25T20:46:45.120Z
did you ever resolve this problem? I am sometimes experiencing a similar issue.
user84207
<temperature><thermal-runaway>
Changing the temp from 200/60 in any degree triggers thermal runaway
MJH12
# Changing the temp from 200/60 in any degree triggers thermal runaway

(Asked by: username_0 on 2022-05-10)

I am new to 3D printing and having a strange issue I don't understand and would love some help with. I have an Ender 3 Pro and when I use the settings 200 °C & 60 °C it prints fine. However, I want to change the bed to 55 °C as the bottom layers are melting a bit. I changed this in Cura to 200 °C & 55 °C and get a thermal runaway after 20 minutes or so. I hit resume and the same thing after about 20 minutes, however, the times vary.

I did a PID using the same set temps 200 °C & 55 °C and still thermal runaway. So I changed all the numbers back to 200 °C & 60 °C and ran a PID on this original temps and ran perfect (except for the first layers melting a bit)

The odd part is the bed temp holds fine when adjusted to 55 °C, it's the hot end that starts to drop a few degrees (5 degrees) which triggers the runaway. Is this a fan issue (currently at 100%)? Before I started changing things I wanted to ask here.

Looking forward to your feedback. BTW I am able to change the PID right on the machine and have no experience altering G-code or the knowledge but am willing to try?

**Tags:** temperature, thermal-runaway

> **Comments:**
> **username_1**: I assume you're getting a thermal runaway error.  Is there any evidence of the printer actually starting into thermal runaway?  
> **username_1**: Also what is the model of your 3D printer?  Your temperatures sound like you're printing PLA.  
> **username_0**: yes running hatchbox pla black. ender 3 pro  is all i know. Yes its a thermal runaway. I have been watching it and seeing the hot end temp drop.  
> **username_2**: i thought a thermal runaway was when things get way too hot?  
> **username_3**: The bottom layers experience elephant's foot, not melting. PLA only melts at ~180 °C  
> **username_4**: did you ever resolve this problem? I am sometimes experiencing a similar issue.  

---

## 2 answers

### Answer by username_5 on 2022-05-11. Score: 1

Sounds like a thermostat problem, 60 degrees shouldn't be melting the first layers with PLA.

I would try manually checking the temperatures and move forwards from whatever results I got from that.

If the heats were fine, then I'd be inclined to return it as a faulty unit if it's under warranty.

> **Comments:**
> **username_0**: I have changed the thermistor multiple times and definetly not. Im thinking its a G-code issue.  
> **username_5**: How could it be gcode? The gcode just sets the temperature right at the start if you're not doing fancy modifications to it. Have you tried flashing the firmware? I was going to suggest that but unsure what it would do to the warranty status  
> **username_0**: I bought this unopened from a third party. I have not flashed the firmware. I will look into that. I have printed 4 10+ hour prints all beautifully since I started this thread. All at 200/60. so strange that changing the temp down 5 degrees on bed drops the hotend. What do you think about it being a fan issue? Maybe all both bed and hotend fans are firing at the same time?  
> **username_5**: I don't know sorry, but the firmware controls the fans. I have never had a fan issue so have no experience with that. The fact that the issue is intermittent could be a capacitor issue, but thats a board problem. If your board is playing up then you need professional help unless you're an electrician  
> **username_5**: I still think there is something wrong with your heat readings, I have done 2, 3 and 4 day prints that don't have any melting bottom layers at 60 degrees bed  
> **username_0**: Theres really no melting at all. I think im being a perfectionist.  
> **username_5**: Nothing wrong with that at all... good luck printing  

---

### Answer by username_6 on 2023-09-06. Score: 0

Could be a bad thermistor, could just need a pid tune. I would start with pid tuning it, if that doesn’t work I would swap it for a new one. Don’t forget to pid tune the new one if you end up going that route.

> **Comments:**
> **username_7**: The OP states that they have *already* changed the thermistor (multiple times) in [this comment](https://3dprinting.stackexchange.com/questions/19368/changing-the-temp-from-200-60-in-any-degree-triggers-thermal-runaway/21404#comment37044_19370)  

---

