Thanks everyone for chiming in.
Confession time. In trying to resolve this issue I was looking everywhere and I came across a post somewhere about 'another switch'. Our rig was delivered to us winterized, including from the dealer. It turns out there is a switch on the heater below the element that should be 'off' when the tank is empty (i.e. winterized). I never saw the switch, and was never told about the switch at delivery AND it was cover in silver foil tape from the factory so it was hard to see. Needless to say, when I peeled the tape off, the switch was in the OFF position. I turned it on and voila, hot water. I missed it, the tech missed it and his boss at CW missed it (he was giving suggestions to the tech over the phone).
Checklist item one on any electrical device not working...is it ON? OOOPs!
Those of you with a Suburban 12 gallon HW heater, go check out your switch.
