A spa control system where the spas heater is disconnected from the power source anytime the water in the heater is at a higher temperature than that set by the user by a prescribed amount. Since the control system has a regular temperature managementsystem this will only occur because of a problem in the spa or the control system itself. Independent paths between a pair of temperature sensors in the heater and the relays that connect line voltage to the heater are provided to meet the safety requirements of UL. Two sensors in the heater are co-located in a metal tube, placed near the heater.
