Frage Y axis homing....

Hi
Just completed the build on v2-840. All working great!! cut my first piece - JULIE that's my wife's name. Call me old fashioned but hey....
Anyway when homing in UCCNC the machine homes as its supposed to but the Y axis remains at zero. I thought that only the X & Z axis went to zero and the X axis was set to the machine limit of just under 840.
I have tried loading the 840 profile that was supplied with the machine but it does not seem to put the correct values in.
Is this correct as I'm only just starting out and doubting just about everything.

If so what's the likely problem? Can I set the configuration manually?