Brass, or Di-electric union

Rich Kontny_3

Usually not an issue in a closed loop system. If a great deal of makeup water is needed then you may need dielectric protection

Rich K

Wayco Wayne_2

I have installed

more than a few mod con boilers on existing gravity pipe systems. I love the over sized radiators and the lower water temps they can work at. In the past I have always changed from the old steel pipe to the new copper pipe using a brass ball valve or brass fitting to separate the two. Today I was told that I should use a di-electric fitting in this instance. What do you guys do. What is proper and what is best? WW

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Billy March_2

dont use em

I am not a fan of the dielectric union and just recently I was reading a post from ME that said those unions wind up doing more harm than good. I myself usually use a brass fitting to make the transition but Mark said to use a yellow brass coupling because it would be neutral between the two different metals.

Unknown

I don't use them

I don't use them at all, just male copper adts into black female fittings or coulpings. Never had problems.

[Deleted User]

i've used both di and brass transitions,

but i haven't seen enough to say good or bad. and if i'm remembering correctly, i used the steel to brass ones for the added 'comfort'. 2yrs and still no leaks. knock-knock. do i completely believe in the 'science'? no. sound like ju-ju

Mark Eatherton

Just curious Wayne...

Who told you that?

The code accepts the use of brass isolation between di-similar metals in closed loop systems.

An AHJ per chance?

ME

Wayco Wayne_2

I had a leak

on the barb connection of a condensate pump that would seep water when the pump ran and left a trace of water on the basement floor under the boiler. The customer is having some an addition done and the GC had his hvac guy there. She asked him to look at the water and who started critising my work. The customer was upset and she called me. I was 3 blocks away and shot right over. He was an **** who was showing off how smart he was. He told me I should have used di-electric unions. He also told me that I should run my pt lines within 6 inches of the floor. Duh! I had left enough room for a bucket. I kept my cool but wish I hadn't. I'm still mad that he would try to curry favor with my customer by trying to cut down my work, and then faced with me, act as though he was trying to help me. Here's a picture of the job when it was almost done. I hadnt run the PT line yet. Mark I would like to find the thread on di-electric unions. What is the problem with them. WW

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[Deleted User]

I had a leak

and if i'm correctly remembering the thread, that was the gist on dielectrics; they'll leak bec of the gasket degradation due to high temp. but there are two types of gaskets so, that idea may not hold water <;-)

[Deleted User]

Leaks happen.....

As my dad use to say, there are two people in this world that don't have leaks. People that don't work with water, and plumbers that lie :-)

In the International residential code book, section P2904.17.1 Joints between disimilar metal pipes shall be made with brass fittings or di-electric unions.

Section M2002.4 states, Discharge pipe shall be piped to WITHIN 18" of the floor.

Lastly, every di-electric union I have seen was SO corroded internally, that I was amazed there was ANY flow through the union at all. ALso, as others have pointed out, I have yet to see a di-electric union that DIDN'T leak. And NO leak is a good leak.

I think I'd tell the homeowner that your system is in full compliance with the code, and that the other contractor ought not attempt to criticize other peoples work in an effort to gain their confidence. The installation looks fantastic to me.

People who live in glass houses shouldn't cast stones...

ME

[Deleted User]

was SO corroded internally

ahhh, thank you master. eye will look with my internal i to see better

[Deleted User]

And...

from the outside as well. I don't think internal corrosion is as much an issue with closed loop systems as it is potable systems, but I actually got a city council to quit requiring the use of dielctric unions on water heaters at one point in my life (a LONG time ago).

THe biggest problem they pose in closed loop systems is leakage. That, and due to the lack of oxygen, they really aren't necessary.

I have some pictures of the insides of some around here somewhere...

ME

Wayco Wayne_2

Mark

Thank you for the codes. I E-mailed the customer and informed her. She loves her boiler install and this guy did not take her feelings into consideration. She was relieved to hear the truth in code. The install has been through 2 Winters now and has saved her about 200 a month since the installation. I took out a 500,000 btu cast iron beastie and put in the 175,000 Prestige. On design days the boiler does not shut off. (Yikes! that's close) She had a blower door test done this spring and the energy audit guy found no insulation in the attic or crawlspace. Next Winter she will save even more. WW

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Mark Eatherton

Glad I could help Wayne...

ME

tim smith

Wayne, I dont mean to be picky but the pumps really should match

in color to the flanges! :O

Wayco Wayne_2

Tim!!!

You know how sensitive I am about my installs. Stop being so picky. Stop it!!!! ACK!!!!!

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scrook_3

and next...

he'll want the copper tubing and pump J-boxes to match too!

With attic insulation it should be REALLY sweet!