Water heater install (California)

[Shopco]

14 years I installed the water heater using copper pipe (no flex line) to dielectric unions installed on the water heater.



When I attempted to replace the water heater the unions were welded together. They came away from the heater ok but would not disassemble as designed; I had to cut the copper pipe. Even when taking the unions to the bench vice there was no separating them. They were heavily corroded.



I am endeavoring to prevent a repeat of this situation and want comments on my plan, which is;

[copper pipe] to [dielectric union] to [12" neoprene hose with 316 stainless steel fittings] to [water heater].



What I want to know is if this will eliminate the corrosion on the dielectric unions.

 

[Reach4]

[copper pipe] to [dielectric union] to [12" neoprene hose with 316 stainless steel fittings] to [water heater].

You want corrugated stainless or copper connector lines -- not rubber with a metal braid. Click Inbox, above.

I don't know about whether dialectic unions would be helpful. I would guess not, but I am not sure.

 

[Sponsor]

 

[Terry]

In California they use flex connectors and earthquake straps because of the earthquakes that they have. It's that way on the entire West Coast.

Water heaters come with dielectric nipples which work fine with flex connectors. I quit using the unions decades ago because they close off and prevent water flow.

 

[Shopco]

You want corrugated stainless or copper connector lines -- not rubber with a metal braid. Click Inbox, above.

I don't know about whether dialectic unions would be helpful. I would guess not, but I am not sure.

Why corrugated? Not challenging; seeking knowledge

 

[Reach4]

Why corrugated? Not challenging; seeking knowledge

Doesn't degrade and put black bits into your hot water.
Usually larger ID, which helps lower turbulence, but is that enough to overcome the corrugation? I don't know.

 

[Shopco]

Thank you Reach4 for your interest in my situation. Neoprene shedding: huh, I never thought of that.

Research indicates excellent resistance to heat and ozone. Pressure rating is nearly 2x needed. Possible hardening over time but that should not be a problem in my case since there will be no bends . What does raise a concern is its sensitivity to chlorinated water. I have not tested our chlorine concentration, but the city reports 0.46ppm average (not that tells me anything regarding its effect on neoprene).

As far as the flex connections you suggested, they do indeed look like high quality items however, I do not see them working in my case. There is only 12" between the 1" ball valve and the water heater. I have installed SS ¾" flex with a 360° loop as a temporary fix until I get sorted but it is causing a severe water hammer, necessitating closing down the ball valve to reduce velocity.

P.S. hose is McMaster-Carr item No. 5291K57

 

[Dj2]

Corrugated flex is code in CA. Rigid pipes are not.
I've been using copper corrugated connectors since 1976, which are code compliant. They come with 3/4" black washers, that easily last the life of the water heater. See Terry's picture.
They come inn different lengths. If you go from 1" you will need a reducer to 3/4".

 

[JerryKrinock]

I understand that the dielectric union is required when joining copper to steel because these are dissimilar metals. But if I connect from copper to a stainless steel flex, then to a steel nipple on the water heater, and the stainless steel flex looks like it has a brass nut on each end, that is a lot of dissimilar metals touching one another! Do I need a dielectric joint of some kind if using a stainless steel flex like this?

(I might be wrong, but I prefer a stainless steel flex to a copper flex because I think that, in general, stainless steel is stronger and more corrosion resistant than copper.)

 

[Onokai]

I have always used Corrugated flex as it is code in CA,
They work well last forever and we just had a 6.4 earthquake this week and my 80 gallon Rheem solaraid tank and 40 gallon Rheem made it thru great. Both are strapped in to wall and supports.

 

[Terry]

The copper and the stainless corrugated flex connectors are dielectric on the ends. I normally use 24" flex so that I can make smooth bends.
The braided supplies break down on water heaters and people find little black specks in their hot water over time. The black rubber breaks down.

The ends are dielectric. They last as long as the water heater.
The galvanized nipples that come with water heaters have plastic liners. I've been doing this for 50 years now. Are you trying to catch me on something that the plumbers and the manufacturers haven't thought of yet? Good luck with that.
I don't give legal advice, I'm not trained for that. I do give advice on a practice that I've been researching and doing for 50 years.

A new dielectric union above and one 4 years old below.

One more reason we used corrugated supplies that have their own union.

 

[Terry]

A nice basic example of a water heater installation for the rest of the country, not the West Coast though.
We need earthquake strapping and flexible supply lines.

 

[Fitter30]

Buy longer flex lines make a pigs tail ( loop) to shorten the end to end measurement.

 

[Onokai]

I really like the flex lines with lots of play as well. We have had two earthquakes in past 15 days a 6.4 and a 5.4 so they shook the place. My tanks are strapped down tight and lines are all flex with lots of play in them. The 80 solar tank goes into the 40 gal water heater so they are tied down well and the lines have flex between them.

 

[Jeff H Young]

Flexes are code for us, but they are quick and easy, personally I've fixed many leaks at the flexes but they aren't that common and most tanks are in garages . I think they make a decent installation and would be good to use even if not required. We didn't used to be required to use flexes here and we did anyway.

 

[wwhitney]

As to "flexes are a code requirement," is that spelled out anywhere, or just a common interpretation?

Looking at the California Plumbing Code (or the UPC more broadly), I see the explicit requirement for straps in 507.2 "Seismic Provisions." But the only thing I see that could be construed as requiring a flexible connector is 507.3.1 which says in part "he appliances and equipment shall be supported and shall be connected to the piping so as not to exert undue stress on the connections."

Which isn't explicit. You could argue that if the water heater and the pipes are both securely strapped to the same part of the structure, then they are going to move together, and there will be no "undue stress on the connections."

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Cheers, Wayne

 

[Jeff H Young]

Not sure Wayne I really like to know these technicalities for a fact and not just hearsay so I like that challenge.

 

[John Gayewski]

Yeah I only ever remember reading that the water heater be strapped down.

I've read the whole UPC, but digesting it is another story. I think would will take more years of referencing it. It's amazing how many things I remember incorrectly or slightly distorted.

 

[Jeff H Young]

Yeah I only ever remember reading that the water heater be strapped down.

I've read the whole UPC, but digesting it is another story. I think would will take more years of referencing it. It's amazing how many things I remember incorrectly or slightly distorted.

That's a major reason I like this site, I will say that on big jobs often spec out flex lines on plumbing or HVAC.
I found what bI call a screwup in CA plumbing code today going back to 2018 CPC and sediment traps on the gas lines requiring the gas flex be downstream of the dirt leg. don't know how many I did wrong but its changed now but I never know which codes are adopted. I've really had to figure this stuff out myself and some stuff I still haven't figured out