My system showed a FL, I changed the pressure switch, It kinda worked for a couple days but now I have the same problem. If I turn the power off and back on it runs a couple minutes and comes back on [/code]

Two things, (you didn't say if this system has a circulation pump), I'd first ensure that the setting on the pressure switch isn't too high, (more than 2 psi is usually a bit much). Otherwise I'd be sure that there's enough pressure running through the heater from the pump. Be sure you've got enough flow... (that's what the FL is telling you).

I am getting the FL in the display of my tub as well. I have read the posted answers and i will look at the pressure switch, but as far as checking anything else, talking to a guy that does not know much about tubs, is there anything i can do.

thanks.