Spa electric heater system using multiple spa heaters

A process for electrically heating a spa having electrically operated devices connected thereto, such as one or more water pumps, lights, a heater, in an environment in which there is insufficient current to operate all spa devices simultaneously comprising:

• providing at least two individually controllable electrical heaters to said spa comprising at least a heater number one and a heater number two;
• determining the individual devices attached to said spa including said at least two electrical heaters;
• determining the amount of current available to the spa;
• determining the amount of current utilized by each of said individual devices and storing information regarding each device and the amount of current used by each device, and the amount of current available to the spa in the memory of a microprocessor;
• initially deactivating all spa heaters;
• ascertaining if spa water is below a desired set temperature and if so:
• determining which devices are activated and calculating the amount of current being used;
• subtracting the amount of current being used from the current available to the spa to arrive at a residual current available;
• determining if the residual current available is greater than the current used by heater number one:
• if the residual current available is greater than the current used by heater number one, activating heater number one;
• subtracting the amount of current used by heater number one from the residual current to arrive at a first reduced residual current;
• determining if the first reduced residual current is greater than the current used by heater number two;
• if the first reduced residual current is greater than the current used by heater number two, activating heater number two and returning to said ascertaining step;
• if the first reduced residual current is not greater than the current used by heater number two, return to said ascertaining step;
• and
• if the residual current available is not greater than the current used by heater number one, determining if the residual current available is greater than the current used by heater number two and, if so, activating heater number two and if not, return to said ascertaining step.