Dieletric unions

Jeff_11

When installing gas water heater with copper piping do I need dielectric unions on cold and hot pipes at the heater.

George @ Dynamic Plumbing

Dielectric Unions

Jeff:
The answer is yes, you would use a dielectric union or coupling between every dissimalar metal connection.
So unless your water heater is made of copper like your water piping you need dielectric connectors.

Just curious why a licensed plumber isn't installing your water heater, as they would know not only this but all the rest thats required to keep you and your family SAFELY in hot water.

Best of luck and have a Dynamic Day
George

Jeff_11

I'm not installing one . The heater I have at my apt. doesn't have them . But I've seen them on newer properties.

Larry_7

The dielectric debate

I enjoy all the back and forth on this issue. From factory dielectric nipples pre-installed to unions. We usually just use brass adapters but not even sure they're really neccesary. I've seen copper adapters screwed into the tank and copper near piping joined to galvanized with copper still going strong longer than when using dielectrics. I've seen pics on this site where dielectric unions rotted out after a few years. Some heaters with the dielectric nipples actually say in the literature that dielectric fittings not needed. There is a broad base of opinion on the subject. Brass adapters are accepted around here but exp. tank not enforced. Go figure. It's OK to risk overpressuring the vessel, dump water from the relief valve, and void the warranty as long as the dissimilar metal issue is addressed.

The science of electrolosis is over my head. Maybe more informed ones will jump in. It seems that I heard or read that regardless of dielectric fittings, the fresh water acts as a conductor that electrically connects the dissimilar metals and effectively renders the dielectric nearly useless anyway. Follwing the code should result in approval from the official, however.

Larry