The only switch that I can see (other than the switch on the back of the unit) is the DSI switch. The DSI switch is the only one with a light on it.
I can't see any other switch that is meant to control the element. To get to the switch on the back of the unit, I need to go under the sink and reach back to the back of the unit. I guess it automatically starts heating with the element once the power is plugged in.
I found a sticker in the cupboard that says the heater is gas only, so it is possible that the unit is a replacement (since it has an element in it). That may explain why there isn't a switch. I could easily put one in for inconvenience once I get it all sorted out. There isn't a breaker for it either.
I will check the continuity and voltage at the element to see what is going on.
Thanks again for the info. I will keep you posted.