There is an aluminum box attached to the bottom side of the heater with some wires running into the end. Does anyone know what this box might be? the box is about 3"X4"X10" or so.
Also how do you tell if you are running on high speed or not? If I push the jets button twice I get water flow and I can add air with the control knob. If I push the jets button to turn it off then I have to push the button twice to get it to run. Also it is running for a couple of hours and then just quitting, it doesn't trip the breaker but just stops and then I can push the jets button twice again and it will start up. The temp is about 100.