my issue is a little different. I have a Solidoodle3.
The heated bed control on the web gui shows 'undefined' and just 'C' it does not have a value.
the funny thing is, the controls seem to work, if I turn the bed on and set the temp, the temp goes on and sets in Repetier-Host. It just does not report back to the web gui.
Extruder temp reporting and action works fine.