Jump to content
Ultimaker Community of 3D Printing Experts

Bed Temp Sensor ER02

Recommended Posts

I have an Ultimaker 2 Extended, and I'm getting ER02 about the bed temp sensor. I've swapped cables as advised by the troubleshooting site, but the error doesn't switch to the nozzle sensor. Am I correct that this seems like a board issue? I really want to get this printer fixed asap. It heats up just fine, but around 90 C the reading will suddenly jump up much faster to something in the mid or high nineties, then the error. I don't believe that the bed itself is heating too fast. I did manage to get one print after troubleshooting in an unproductive circle for some hours, but after that it went right back to erroring. Please, help?

Share this post

Link to post
Share on other sites

more info here: http://ultimaker.com/ER02


This is almost certainly a problem at the bed and not the board.  When things heat up they expand.  A contact along the temperature sensor path is a bad connection and when things heat up and expand it loses connection.  Slowly.  As it loses connection the resistance suddenly rapidly increases and that looks to the logic just like increased temperature.  But it's not increased temperature - it's a slow motion disconnection.


The problem is most likely right where the connector is.  Also it could be a trace on the board or it could be the sensor.


I'm an engineer - if you or someone you know is good with a multimeter you can fix it yourself pretty easily.  This is like a 20 minute fix for me.


I would take it all apart so you can get access to the tiny little PT100 chip (it's the only chip on the board - you can follow the traces visually that the smaller two wires go to over to that chip.


 I would first just reflow the solder at the PT100 chip and at the connector.  It's almost certainly the connector.  There is mechanical stress there when the board moves and several people have had problems on the forum with that connector not soldered well enough.  At least on the UM2.  Basically the UM3 is identical in this regard and I don't remember if anyone has had a problem with the UM3 connector but if they get what you describe it's probably the same spot - the connector.


99% chance this fixes it.  If not I would connect it back up and just hanging (not screwed in) and connect the larger two cables to a 24V 200Watt supply (not easy to find) and heat it up to 100C and while that is happening measure the resistance of the PT100.  It will slowly increase from 109 ohms at room temp to around 200 ohms when hot but then suddenly sky rocket to infinite ohms.  At that point you can probe each point along the path and find out where the failure is exactly.  It might be that you need to run two tiny wires from the connector over to the pt100.  In fact I'd just run those 2 wires if the reflow trick doesn't work and not even bother heating it.


OR you can get a new bed heater from your reseller.


  • Like 1

Share this post

Link to post
Share on other sites

Thank you for such a comprehensive answer!


I read this wrong the first time and took apart the main board, looking for the PT100 chip. The good news is that all none of the joints there look dry.


After reassembling all that, I took a look at the proper location, and ran into what I imagine is a really stupid problem -- I honestly don't know how to disassemble it to a point where I can reflow the solder. Here's a photo of what I'm looking at -- pulling on the wires doesn't seem to remove them.




Share this post

Link to post
Share on other sites

Do you have a multimeter?  Disconnect this cable at the *other* end underneath the printer and measure the resistance there.  It should be around 100 ohms.  If it's failing it should be well over 1000 ohms.  While one person holds the multimeter to the two wires, another person needs to push and poke at these connections.  Push quite hard - maybe 1kg force.  Hopefully, the resistance will jump from around 100 ohms to infinite.  when that happens you found the problem area.

Share this post

Link to post
Share on other sites

Alternatively, turn the printer on and go to SYSTEM and go to where you set the bed temperature and leave the temperature at 0C but have one person watch the temperature while the other person pokes at these connections.  The problem with this approach is that every time the temperature goes over 700C you will then probably have to reboot your printer and start over until you find the problem spot.

Share this post

Link to post
Share on other sites

I have error showing.

ERROR sensor BED


The problem is its is intermittent .

I have re-solder connecting block on bed.

Checked board connection .

Tested for O/S wires from board to bed.

I getting a reading of 109ohms resistor? on bed.

I can get one print (first of the day) , try to print again some times OK some times fault.

The printer has done several hundred hours

Is it the board or bed?


Ultimaker 2+

I upgraded to + months ago


thanks gromit

Share this post

Link to post
Share on other sites



Just want to add to this, as I am experiencing the same symptoms as gromit on an Ultimaker 2+ Extended, the one with the connection style shown in Megatarts image.


Similarly I can do one print each day, then the error persists for some time afterwards.

I soldered jumper wires directly from the connectors to the PT100, and still the error persists.


How likely would it be that the PT100 itself has failed somehow, or the sensor wires from the bed?  They do seem to be bending nicely without obvious kinks or strain.


As an additional note, I've only ever seen the error thrown when the bed has fully descended to it's lowest position, not during a print.





Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Our picks

    • Ultimaker Cura | a new interface
      We're not only trying to always make Ultimaker Cura better with the usual new features and improvements we build, but we're also trying to make it more pleasant to operate. The interface was the focus for the upcoming release, from which we would already like to present you the first glance. 
        • Like
      • 130 replies
    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 replies

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!