Ender3 Control Board Options


My Ender3 has been sitting idle for a couple of years. I am starting up with some 3D printing projects again. I am connecting to the printer via OctoPi and it reports the lack of runaway protection on the printer. Question I have, what are my options to upgrade the main board to provide runaway protection (Marlin firmware?) and also support a filement sensor?

I am asking because my printer runs unattended in a remote location which I monitor via OctoPi camera.


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HI @Oodimdemus Welcome to the forum, I’m glad you found us.

I am going to state the obvious first please I do not mean to be pedantic. Please don’t ever run a printer without thermal runaway protection enabled. It’s just not a good idea.

That being said there are a couple of solutions for you. As you mentioned a new board may be an option, Ender 3 boards are available and they will all have thermal protection enabled. On top of that, there are so many options out there for firmware with or without BLtouch, Filament sensor or other options. Easy enough to get and install.

With the newer boards, you will also get the advantage of quiet stepper drivers. faster processors, more available options.

You can simply burn new firmware to the board you have however suspecting it to be a bit board you may need a bootloader to get firmware onto it. not to mention the hours you will need to put into creating the firmware, to begin with including troubleshooting it.

Hi Jason,

I am quite familiar with Arduino (which I think the Ender 3 hardware is related to), but with a few projects having queued up, the last thing I want to do is now enter some length of time where I need to “fix” things before they work properly. Hence, I am dismissing the idea of burning bootloader and different firmware to ensure I have something that does work to fall back on.

Are there a decent board to look at or recommend that have the additional inputs needed for filament sensor (I haven’t thought of BLtouch but being prepared sounds nice) but is otherwise “plug and play” in the existing Ender 3 case and compatible with its connectors?


I think he meant to say “8-bit board”.

Thermal runaway is merely a software subroutine that checks if heat was applied and if the temperature is increasing. If heat was not applied and the temperature is increasing, you have a problem, so shut down the printer. It’s not a difficult concept to program in, so just about any firmware could be modified to include it if the developers of the firmware thought of it.

The only limitation is the memory on the controller board. Obviously any additional programming loops require additional memory, but thermal runaway is fairly minimal in its most basic form.

I agree with @Jason, that you shouldn’t entertain running a remote printer without it.

So, check your board revision number, get the latest firmware for it and read up on what features it comes with.

Obviously, you have to weigh the value of whatever project you’re working on against the cost of buying a new board primarily just to print it, but also keep in mind that a modern, full-featured board, which may be overkill for an Ender3, can be used later to upgrade another printer, if applicable, so in that sense, it may be worth spending the money just to have up-to-date parts.

The Ender 3 I have is an 8-bit board with Mini-USB connector, purchased back in January 2019. I haven’t found any official firmware updates for this.

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Creality has a 32 bit board that has many more options than stock. not sure about fillament runout

The Creality 4.2.2 or 4.2.7 boards and others have thermal runaway protection and should fit an Ender 3. Also a filament sensor and BL/CR Touch probe can be added but will need the appropriate firmware.

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Hi @Oodimdemus as Loosenut has mentioned above, 4.2.2 or 4.2.7 are good replacement boards.

The Official Creality crossref for a silent board on an ender 5 Pro is a 4.2.7.

I do not have the pre-flashed one in stock right now that will be “bolt-in” however you can order this one linked below and the firmware is an easy install from Crealitys website.



Choose, Ender series, then at the bottom, you will see ender 5 Pro, Choose the top one, 5pro 4.2.7.

Hope this helps

Given a choice and assuming it will work in an Ender 3 which it should (ask the pro’s first) then go with the 4.2.7. They are suppose to be more reliable. 4.2.2 steppers have been known to fail sometimes probably insufficient cooling. That’s why I changed the power supply and motherboard cooling fans from the stock 40mm to 92mm Quiet fans.

P.S. there are many other advantages/reasons for upgrading to a 32 bit board.

The biggest advantage is Quiet, Past that does give you more processing power and generally more expandability for items such as BLtouch and Filament runout sensors.

Also dead simple to upgrade the firmware with a built in boot loader.