Since this is non-potable is it correct that I can not piggy back on my potable water heater?

Hello - your correct, these components do not comply with Low-Lead law because they are designed for heating only and not used in potable systems. If the water heater was independent and only used for heating then you can use, but it cannot be used for heating and potable use. Thank you for your interest in our product and if you have any further questions, please contact our Customer Service Team at 1-877-700-4242 and we would be happy to assist you!