Louisiana/New Orleans code for Backflow preventer on solar hot water systems

michael_34

I have been talking with a gentlemen in New Orleans about solar thermal. He is having problems selling the systems because the Dept. of health demands that a backflow preventer is put on the main water line coming into the house, thus creating a higher cost to the customer.



I understand why back flow preventers are put on residential and commercial water systems, (kind of, I don't understand where contamination would come from) But why, on a solar thermal system would you need a backflow preventer on the main water system coming into the house?



Here is a link about the Louisiana code:<a href="http://www.lses.org/problems-heating-up-for-solar-water-heater-installations-in-la/">http://www.lses.org/problems-heating-up-for-solar-water-heater-installations-in-la/</a>



I posted this on the Solar page and receive no replies so I thought I would try the boiler folks.



Thanks,

Michael