In the following video he specifically talks about dielectric unions, granted he references their use for gas lines but the same can happen with your water heater and the incoming cold water line.
The 6" rule they were talking about women and their minimum lololololoYou see I've heard people argue that, too.
I've heard most of my mentors say you need at minimum 6" of brass, but then people here say that a simple brass FIP will work, or a brass union.
Does the 6" rule really matter that much?
I think you should just install it per manufacturers instructions with the dielectric unions and if it fails before end of warranty make sure they pro rate and maybe try to get some labor compensation.Really makes you wonder if we're sitting here trying to figure out a problem that there really isn't a solution to. I understand electrolysis and all that, but clearly the methods that have been attempted in the past to remedy this only amounted to a bunch of crap