Thanks, I got it working following your instructions. Being new to this tool it was a bit of a challenge to find the various menus and selections to make. I think the following will help other new users. Some of us need to hand held through the process :) like a child on a busy street. :)
The process I followed to get the local Host-Repetier printer serial port working:
Connect serial port to printer and power on your printer if not already running
In browser window find "deactivate printer" and click it. This will result in a browser message "Connection Lost"
In the Repetier-Host "Server" drop down menu select "Stop Local Server"
Then make sure in Repetier-Host "Printer Settings" to select the printer profile for your printer (if not done already fill it in now), press okay
Then close Repetier-Host program and start it again.
The manual control should now read "Idle" (not Disconnected)