Hi...Have an indoor pool w/ hot tub. Will be installing a Hayward natural gas boiler soon for pool. Retailer says I cannot have this boiler heat both the pool and hot tub. There is a switch that will recognize the units but he states that I cannot do the mixing thing with salt water then switching toheat the spa. This would save me $$$ as I now have to purchase an additional heater (electric 11kw) to heat the tub. Can You help me. Am I about to do the right thing.....Thanks, Ed in Winnipeg, Mb, canada