I just inhearated a Grandee 1999 vintage. Hooked it up. Jets run when turned on, light works well, and the clean function works too. The Problem is neither the heater nor the circulation pump come on at all. I jumpered them each out individually and they work.

Could this be a bad control board? Or perhaps something simple like a themp sensor? how can I tell before I drop the better part of $500 on a new board?

Not sure what you mean by "jumpered out the circ pump and heater and got them to work".

Sometimes when a tub sits for a while the circ pump needs a little 'tap' with a screwdriver or something to get it going again. If it is not working then the heater will not work.

If the circ pump is not working then you need to test for 110volts at the terminals where the circ pump wires attach. If there is voltage and it is not working then it is bad.

You can also test the heater for continuity with a meter to see if it is good. Depending on whether or not the heater has been replaced it may have a high limit reset button on the heater itself.