We have a 2004 jacuzzi J365 hot tub. In Jan we noticed the temp going down so we emptied the hot tub and drained all of the pipes. Last week we opened it up and saw the ground wire to the heater had detached. We reattached the wire, filled the hot tub and started it. After 2 days the temp went from 65 to 86. Not sure if it was the outside temp heating the water because it was in the 80s both days. When we put our hand where the heated water comes out, it doesn't seem to be hot. Any suggestions on what to do would be greatly appreciated before we call someone.