DiElectric Union or Brass Nipples

[Chefwong]

Let me hear is. DiElectric Unions seems to be more common.

I'm hardpiping direct to the water heater.

I plan to just swap the stock nipples with brass nipples.
Any reason to NOT do this and go with dielectric unions right off the factory nipple stubs ?
I also read that on some water heaters, the nipples cannot be REMOVED as it's part of the dip tube

If you put a brass nipple to the tank, is there is a slight possibility that it may corrode the steel on the tank

Thinking Hex Nipple might be easier to *turn on* versus a standard nipple.
Thoughts

 

[Terry]

The nipples that come with the tank are plastic lined. Why change them?

 

[Sponsor]

 

[Chefwong]

Those plastic lines are poop though ....

In our vacay home, we had a faulty heater.
I had someone replace it ~installed~.
Heater had the dielectric nipples - aka, plastic lined.
Plumber soldered copper directly to it factory plastic lined galv. nipples
Years later, one of those nipples rusted out.

BTW, for all you RHEEM installers out there who have changed out the nipples, can you confirm.
I read that Rheem has put hard-set threadlock in their nipples as of 2014, and it's quite a near to replace..

 

[DonL]

Why would anyone solder to it ?

I need to go back to school I guess. I must have missed a class.

 

[hj]

The nipples could have both the dip tube AND anode rod attached to them, depending on the brand. IF some "idiot" soldered to the factory nipples and melted any plastic parts on them, that is NOT a defect in the heater, it is a defect in the worker. A sensible installation will have unions at the tank, so the least expensive way is to use dielectric union on the dielectric nipples that come with the heater.

 

[Chefwong]

I don't think he did solder directly to the nipple. I recall as we were reviewing the final setup, he said something to the extent of I was careful due to the plastic lining. Whether or not he soldering the cup/pipe and then put in on the WH nipple is ??
Regardless, one of the nipples had rusted out.

I pulled up the specs on the Rheem unit I'm tentatively considering and the stock anode is on it's tap.
You can add a second anode as a option. I think between the ~questionable~ hard set threaded nipple, I'll skip adding the 2nd anode and just swap it to a new one in the standard anode port in year 4-5 of ownership.

So I guess unions are the standard fare to go .

 

[Terry]

A delectric union that has been in use.

Are they really doing anything. The ones I pull out are sometimes closed almost all the way with corrosion and rust. I quit installing them years ago because they all look like this in a short period of time.

 

[Master Plumber Mark]

Nice pictures Terry... I personally would hook up to the plastic lined dia-electric nipples that the water heater comes with
And I would use either copper flex connectors of SS braided connectors... they work much better than the unions like Terry has posted

 

[Chefwong]

Just wrapped up doing the hw tank install yesterday. Used RB nipples out to hard copper.

Saw some weird things while breaking down the previous plumbers work.
One thing which was super weird and obvious. On the cold water side, he use a black reducing coupler which was a obvious ?
It went from brass pipework - black coupler-copper-direct to the steel nipples.

I redid a majority of the gas lines. It was a hodge podge of fittings, with everything from black iron, to a street 90 in brass, with a galvanized 90 elbow. There was a 3 inch variation height difference between one end of the union and the latter side---and this was the gas line.

 

[hj]

Dielectric unions are really just cosmetic items to make inspectors happy. Their degree of separation between the two materials is much too short to be effective.

 

[Slomoola]

A delectric union that has been in use.

Are the really doing anything. The ones I pull out are sometimes closet almost all the way with corrosion and rust.

Mine had these same unions. I had even more corrosion than in these pictures. Inside both the hot and cold nipples was nearly blocked with a rusty brown buildup of corrosion. You couldn't stick a flat blade screwdriver through it. Surprised I had any hot water. Best to install 3/4" brass nipples. The tank I replaced was made in 1998. That black rubber washer was all gimped up like this one. Total substandard part IMO. Brass nipples all the way.

 

[Plumber69]

If the copper pipe isn't reamed out on the fitting closet to the tank nipple it will build up a pile of rusty gunk.

 

[g20zoom]

My Rudd/Rheem heater bought 6 years ago from a plumbing supply house, has one nipple heavily corroded on the outside already. I guess I'm going to brass next! assuming I can remove my old one. I just posted for advice in the other DIY Advice forum. I maintain a handful of different heaters...and haven't seen this problem in 20 years. I guess the materials used are getting worse!

 

[g20zoom]

Do all Rhuud/Rheem have a dip tube? I was thinking...how does the dip tube connect/fit into a brass nipple? Do you literally just push it up in there? I wasn't sure if the diameter will differ from that of the plastic lined dielectric nipples the heater came with.

 

[Master Plumber Mark]

most heaters have... a built in dip tube attached to the bottom of a dialectric nipple.... which is the best way to install one...
they are secure and work very well ..... We have not even had an issue with a dip tube in decades