<p>Get this back to your supplier and claim the warranty, don't tinker with it, you should get a replacement. Without input, the bed should never heat up, something is obviously broken or installed incorrectly.</p>

CC BY-SA 4.0
2024-06-05T04:08:16.437Z
2024-06-05T04:08:16.437Z
0scar
<p>When there is no connection between the bed thermistor contacts, the Ender3 runs into thermal runaway protection.
Two small white wires should run from your motherboard to the heated bed and is probably disconnected somewhere.
The Ender3 has some places where this fragile cable can be pulled by the gantry, so look out for a break in the wire and also at the contacts of the (glass) thermistor)
A replacement thermistor is cheap, but look out for the right one as there are many different resistor values available.
If you have a multimeter, you can try measuring the resistor between the contacts of the thermistor wire and compare the values to the ones you measure on the wires of the hotend thermistor. They should be in the same ballpark.</p>

CC BY-SA 4.0
2024-06-04T12:02:56.323Z
2024-06-04T12:02:56.323Z
Hacky
<h1>RETURN THIS DANGER</h1>
<p>For whatever reason, the bed is getting power. That means it heats. That means it is <strong>DANGEROUS</strong>. Turn it off, separate it from mains power, don't use it, and return to seller as dangerously defective.</p>
<h3>Possible reasons</h3>
<p>Among many other reasons, these seem to be possible but can't easily be fixed without knowing exactly what you do:</p>
<ul>
<li>The heater control chip is burnt out and does not trigger off.</li>
<li>The firmware is botched and sets a print temperature from the launch.</li>
<li>A wire is connected to the &quot;high&quot; voltage supply instead of the heater port.</li>
</ul>

CC BY-SA 4.0
2024-11-02T14:11:08.900Z
2024-11-02T14:11:08.900Z
Trish
<p>That’s weird. It’s could be a broken thermistor or connection with your mb. Try seeing if these are good and also contact support, bc this is really weird.</p>

CC BY-SA 4.0
2024-06-04T14:12:20.713Z
Welcome to 3D Printing! and thank you for your contribution. When you get a chance, please take the [tour] to understand how the site works and how it is different than others.
agarza
CC BY-SA 4.0
2024-06-04T19:26:05.523Z
Could you [edit] and expand upon your answer, because, as it stands, your answer could seem to be more of a comment rather than a full answer? Also, please don't use text abbreviations (mb, bc), as their meaning may not be obvious to non-native English speaking readers.
Greenonline
CC BY-SA 4.0
2024-11-02T14:09:15.400Z
The bed *showing a wrong temperature*? yes, might be a broken thermosensor. But **heating**?! DANGER.
Trish
CC BY-SA 4.0
2024-06-04T08:31:46.880Z
2024-06-04T08:31:46.880Z
Charged
<p>I have just purchased my third  Ender 3 V2, this time a Neo. After unpacking and assembling it, then switching it on, without any prompt from me the bed starts heating, and carries on heating until it reaches 110 °C when a warning &quot;bed overheating&quot; flashes on the screen.</p>
<p>The hot end reacts correctly to the input on the display but even when I set the bed temperature to 55 °C it ignores that command and carries on to 110 °C.</p>
<p>How can I rectify this?</p>

<creality-ender-3><troubleshooting><safety><creality>
Why is my Ender 3 v2 Neo bed overheating without any interaction?
user43543
# Why is my Ender 3 v2 Neo bed overheating without any interaction?

(Asked by: username_0 on 2024-06-03)

I have just purchased my third Ender 3 V2, this time a Neo. After unpacking and assembling it, then switching it on, without any prompt from me the bed starts heating, and carries on heating until it reaches 110 °C when a warning "bed overheating" flashes on the screen.

The hot end reacts correctly to the input on the display but even when I set the bed temperature to 55 °C it ignores that command and carries on to 110 °C.

How can I rectify this?

**Tags:** creality-ender-3, troubleshooting, safety, creality

---

## 4 answers

### Answer by username_1 on 2024-06-05. Score: 1

Get this back to your supplier and claim the warranty, don't tinker with it, you should get a replacement. Without input, the bed should never heat up, something is obviously broken or installed incorrectly.


---

### Answer by username_2 on 2024-06-04. Score: 0

When there is no connection between the bed thermistor contacts, the Ender3 runs into thermal runaway protection.
Two small white wires should run from your motherboard to the heated bed and is probably disconnected somewhere.
The Ender3 has some places where this fragile cable can be pulled by the gantry, so look out for a break in the wire and also at the contacts of the (glass) thermistor)
A replacement thermistor is cheap, but look out for the right one as there are many different resistor values available.
If you have a multimeter, you can try measuring the resistor between the contacts of the thermistor wire and compare the values to the ones you measure on the wires of the hotend thermistor. They should be in the same ballpark.


---

### Answer by username_3 on 2024-11-02. Score: 0

# RETURN THIS DANGER

For whatever reason, the bed is getting power. That means it heats. That means it is **DANGEROUS**. Turn it off, separate it from mains power, don't use it, and return to seller as dangerously defective.

### Possible reasons

Among many other reasons, these seem to be possible but can't easily be fixed without knowing exactly what you do:

* The heater control chip is burnt out and does not trigger off.
* The firmware is botched and sets a print temperature from the launch.
* A wire is connected to the "high" voltage supply instead of the heater port.


---

### Answer by username_4 on 2024-06-04. Score: -2

That’s weird. It’s could be a broken thermistor or connection with your mb. Try seeing if these are good and also contact support, bc this is really weird.

> **Comments:**
> **username_5**: Welcome to 3D Printing! and thank you for your contribution. When you get a chance, please take the [tour] to understand how the site works and how it is different than others.  
> **username_6**: Could you [edit] and expand upon your answer, because, as it stands, your answer could seem to be more of a comment rather than a full answer? Also, please don't use text abbreviations (mb, bc), as their meaning may not be obvious to non-native English speaking readers.  
> **username_3**: The bed *showing a wrong temperature*? yes, might be a broken thermosensor. But **heating**?! DANGER.  

---

