Why is my 231 display saying "Er01" or "ER02"?
The 231MS and 231RS with display options will both display this error if there is a problem within the circuit board or if there is a problem with the display itself.
ER01 indicates the unit has lost its memory, in a sense. The unit will need to be sent back to the factory to be re-calibrated.
ER02 is also a memory loss error. With the ER02 error, the unit can be re-set by pressing the zero button.
If you need to send the unit back to the factory, a RMA form must be filled out.
Here is the link to the form: https://www.setra.com/support/service