<p>I had a similar issue when printing with ABS, because my print cooling fan only activated once it got to a certain height above the bed. I'd say you need to do a PID tuning session, insulate the bottom of the bed better, and see if you can make sure your cooling fan doesn't blow air over the bed itself.</p>

CC BY-SA 4.0
2019-06-02T07:18:31.760Z
Thank you.  Since I did a pid tuning session everything is good.
2012User
CC BY-SA 4.0
2019-06-01T19:21:25.167Z
2019-06-01T19:21:25.167Z
Nach0z
<p>For people from google:
Go to configuration_adv.h in the marlin firmware source code, and search for &quot;THERMAL_PROTECTION_HYSTERESIS&quot;. Then increase the number. The number is how much degress celsius the temperature can be off before thermal runaway</p>

CC BY-SA 4.0
2022-09-11T21:54:03.200Z
This is the correct answer to the question that was asked. While the solution to the OPs problem was pid tuning, this is the correct place in Marlin to change the number of degrees off before triggering an error.
galamdring
CC BY-SA 4.0
2022-09-12T16:39:48.867Z
@agarza this config changes the sensitivity of the thermal runaway. so its exactly what the op asked
T0biasCZe
CC BY-SA 4.0
2022-09-12T17:26:40.220Z
Ok, I see now. This is basically a "how to fix it in code" solution. Learn something new everyday. Thanks for enlightening me.
agarza
CC BY-SA 4.0
2022-09-11T17:29:50.567Z
2022-09-11T17:29:50.567Z
T0biasCZe
<p>Sometimes I use a DIY 3D printer running Marlin firmware and I have a hard time to set my heat bed temperature. when I set it to 70&nbsp;&deg;C for PLA, after a few minutes it decreases to 67&nbsp;&deg;C and I see these error:</p>

<pre><code>READ: Error:Thermal Runaway, system stopped! Heater_ID: bed
READ: Error:Printer halted. kill() called!
</code></pre>

<p>Since then the communication with printer is lost, the printing process stops and I have to reconnect to serial port... It's a disaster. I guess I need to lower the sensitivity to 3 degrees at least. I don't know how!?</p>

CC BY-SA 4.0
2019-05-07T10:58:15.393Z
Have you PID tuned the heated bed?
0scar
CC BY-SA 4.0
2019-05-07T11:32:26.690Z
aside note: as an upgrade you can add an insulation under your HB to keep the temperature more constant
darth pixel
CC BY-SA 4.0
2019-05-07T11:48:14.403Z
@0scar No, I'm using the default pid parameters. I Thought it would mess it up if I changed them.
2012User
CC BY-SA 4.0
2019-05-07T11:49:55.720Z
@ darth pixel , I'm using an insulator, however it doesn't cover all the surface beneath HB.
2012User
CC BY-SA 4.0
2019-05-07T11:57:16.620Z
First thing to do is do a PID tuning session! :)
0scar
<marlin><diy-3d-printer><thermistor>
How to decrease sensitivity to heat-bed temperature?
2012User
# How to decrease sensitivity to heat-bed temperature?

(Asked by: username_0 on 2019-05-07)

Sometimes I use a DIY 3D printer running Marlin firmware and I have a hard time to set my heat bed temperature. when I set it to 70 °C for PLA, after a few minutes it decreases to 67 °C and I see these error:
READ: Error:Thermal Runaway, system stopped! Heater_ID: bed
READ: Error:Printer halted. kill() called!

Since then the communication with printer is lost, the printing process stops and I have to reconnect to serial port... It's a disaster. I guess I need to lower the sensitivity to 3 degrees at least. I don't know how!?

**Tags:** marlin, diy-3d-printer, thermistor
> **Comments:**
> **username_1**: Have you PID tuned the heated bed?  
> **username_2**: aside note: as an upgrade you can add an insulation under your HB to keep the temperature more constant  
> **username_0**: @0scar No, I'm using the default pid parameters. I Thought it would mess it up if I changed them.  
> **username_0**: @ darth pixel , I'm using an insulator, however it doesn't cover all the surface beneath HB.  
> **username_1**: First thing to do is do a PID tuning session! :)  

---

## 2 answers

### Answer by username_3 on 2019-06-01. Score: 1 | Accepted answer

I had a similar issue when printing with ABS, because my print cooling fan only activated once it got to a certain height above the bed. I'd say you need to do a PID tuning session, insulate the bottom of the bed better, and see if you can make sure your cooling fan doesn't blow air over the bed itself.

> **Comments:**
> **username_0**: Thank you.  Since I did a pid tuning session everything is good.  

---

### Answer by username_4 on 2022-09-11. Score: 3

For people from google:
Go to configuration\_adv.h in the marlin firmware source code, and search for "THERMAL\_PROTECTION\_HYSTERESIS". Then increase the number. The number is how much degress celsius the temperature can be off before thermal runaway

> **Comments:**
> **username_5**: This is the correct answer to the question that was asked. While the solution to the OPs problem was pid tuning, this is the correct place in Marlin to change the number of degrees off before triggering an error.  
> **username_4**: @agarza this config changes the sensitivity of the thermal runaway. so its exactly what the op asked  
> **username_6**: Ok, I see now. This is basically a "how to fix it in code" solution. Learn something new everyday. Thanks for enlightening me.  

---

