Hi, I am getting an 888 error on my display of an older spa (2002). I am unsure if it is a heater that has gone out or the board. At the time that the spa attempts to heat the water I get the error. I have disconnected the heating elements, and the error is the same. (I taped the wires to keep the circuit complete with the heater disconnected.) I can see the water temp on the readout when there is no 888 error and the pump and jets are working. The error occurs when I set the tub to a number where it is asking to heat the water. Any other time the readout of the spa temp is fine, and the other functions work. The spa store said that it would be the board if I disconnected the heating elements; however, if it is the board, why would all the other functions still work on the readout? Any knowledge about this would be much appreciated. Thank you.