Dielectric union requirement in WA

[Alternety]

I am having my water system refurbished. A significant problem exists because of 5 galvanized dielectric unions put in when the system was built. These are all seriously corroded internally and on the threads.

I want them gone. A plumber has told me that they are required by code. The manufacturer of the indirect water heater (SuperStor) says under no circumstances use dielectric or galvanized connections in the water system. Serious damage will occur and your warranty will be void. There appears to be a conflict here. The indirect heater is stainless and requires no internal sacrificial rods.

I have researched and found varying opinions. Some say yes; some really, really no.

These connectors clearly are not satisfactory for use. There should really not be any unions where they are. There are even two of them isolating a brass water meter from the copper pipe.

I would appreciate some feedback from the experts here. When I hire a plumber, I don't want to get into an argument about this.

 

[Terry]

I've never installed a dielectric union. They just close off with rust.
In the city of Bellevue, they want a 6" brass nipple to go between copper and galvaninzed.
You can also use a clear view plastic lined nipple of galvanized like they have for water heaters.

One problem with the dielectric union is the loss of bonding. There is no longer any means of grounding.

 

[Sponsor]

 

[Alternety]

Thank you. That was my feeling. From you it is a conclusion.