The wiring is pretty straight forward. The challenge I had was with the introduction of the PID controller. I've never used or seen one so there was a bit of research to be done. I learned a bunch from the biodiesel and the home brewing communities. If your spa has a plug, or can be wired for one, using that circuit should be just right. I use a clothes dryer receptacle and hot swap the plugs as needed. Insulating the pot should be a big help. I'll be doing that next year.