ER35 - I2C communication error

This message is due to a communication error in the printer. Since there can be several causes for this, we recommend first rebooting the Ultimaker S3 or Ultimaker S5 by using the power switch at the back of the printer.

Flow sensor

The flow sensor connection could lead to an ER35. This could be checked by disconnecting the flow sensor cables from the flow sensor PCBs at the back of the feeders. To do this, you can take the steps listed below.

Note: It is highly recommended to first get in touch with support before disassembling parts of the printer. Our support representatives can advise on which steps to take based on information in your log files.

Disconnecting the flow sensors:

  1. First, turn off the Ultimaker S3 or S5. If you have a Pro Bundle, it is recommended to disconnect the power cable from the Material Station
  2. Use the 2 mm hex screwdriver to remove the two bolts that secure each feeder to the back panel
  3. Keep the feeder close to the back panel and carefully disconnect the flow sensor cable from the PCB at the back of the feeder
  4. To prevent the flow sensor cable from getting stuck between components, tape the connector to the back of the feeder housing, opposite the PCB
  5. Place the feeder back on the printer and secure with the two bolts
  6. Power on the printer again
Remove-feeder.jpg Disconnect-flow-sensor.jpg

Tip: Please note that for disconnecting the flow sensor(s), it is not necessary to remove the Bowden tubes or adjust the feeder tension as in these images.

When the error does not reappear with the flow sensor(s) disconnected, you have found the root cause of the issue. Contact your reseller or submit a ticket via the button above to enquire about replacement parts.

Print head cable

One possible cause for this error is a poorly connected print head cable. This may have occurred during transport of the printer. Fortunately, this can easily be checked by reseating the print head cable:

Note: The above video uses the print head of an Ultimaker 3. However, the procedure is similar for the Ultimaker S3 and the Ultimaker S5. Slide the back cover of the print head upwards to remove it.

If you require further support, please contact us by submitting a ticket.

Please ensure to include the error number (ERXX) and your printer's log files.


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