twall, I am in the same boat except now nothing on mine works. However, I did find out there is a flow rugulatoron top of the heater element housing and a certain amount of flow has to cross it to close the circuit to allow the heater to heat. Its a safety procaution so the element won't over heat.the problem i think i am now having is either in the thermistat controll board on the upper sides. the heater on my unit is a watkins nf1500 my unit is a 110v unit. I have been unable to find this panel anywhere. I even had a spa repairman out and he was even more lost than I was he said he had never worked on one of thes units. Any info will be appreciated