# How to fix and prevent corrosion on water heater lines



## LateralConcepts (Jun 6, 2010)

I'm guessing you can solder based on you mentioned splicing PEX in. I wouldn't do that, but rather cut the copper lines just a couple inches below the top couplings (just below the 90's) then solder on copper MIP adapters. Eliminate the black iron pipe nipples coming out of the heather and replace them with dielectric nipples, then use 18" copper or stainless steel flex supply lines to make your connections.


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## boyfly (Dec 26, 2007)

LateralConcepts said:


> I'm guessing you can solder based on you mentioned splicing PEX in. I wouldn't do that, but rather cut the copper lines just a couple inches below the top couplings (just below the 90's) then solder on copper MIP adapters. Eliminate the black iron pipe nipples coming out of the heather and replace them with dielectric nipples, then use 18" copper or stainless steel flex supply lines to make your connections.


A friend of mine made that same suggestion when he looked at it in person. The only thing that worries me about going that route is that the black pipe appears to be crimped onto the hot water heater... it isn't screwed or soldered on... so I'm not sure how to cleanly remove it without breaking something.


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## LateralConcepts (Jun 6, 2010)

> A friend of mine made that same suggestion when he looked at it in person. The only thing that worries me about going that route is that the black pipe appears to be crimped onto the hot water heater... it isn't screwed or soldered on... so I'm not sure how to cleanly remove it without breaking something.


I've never seen anything like that. Can you take a closer picture showing the nipples going into the top of the tank? Also, how old is that tank? Looks ancient.


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## NHMaster (Dec 21, 2009)

The nipples coming off the tank are perminent and can not be removed. The corrosion is because the copper female adaptors are leaking. take it apart and re-dope the fittings


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## boyfly (Dec 26, 2007)

NHMaster said:


> The nipples coming off the tank are perminent and can not be removed. The corrosion is because the copper female adaptors are leaking. take it apart and re-dope the fittings


I will post some close-ups to confirm that the nipples are permanently installed.

I thought perhaps the corrosion was because of a chemical reaction between the two metals. Is this not the case?


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## LateralConcepts (Jun 6, 2010)

> I thought perhaps the corrosion was because of a chemical reaction between the two metals. Is this not the case?


Yes it is. Electrolysis. You could simply install dielectric unions between the copper and the black pipe, but black pipe should not be used for water if that's what it is. I would get rid of it all together.


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## boyfly (Dec 26, 2007)

Here's a picture at a better angle to see how the black steel nipple is connected to the hot water heater. Also attached is an overall picture of the heater, which is somewhere in the neighborhood of 5-10 years old.


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## AllanJ (Nov 24, 2007)

It looks to me that the black pipe is screwed into the heater.

But this does not mean you can unscrew it easily.

If/when you take apart the copper female screw on adapter from the black pipe up above, the black pipe will have suffered more damage (from corrosion) than the copper piece.


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## LateralConcepts (Jun 6, 2010)

LateralConcepts said:


> Yes it is. Electrolysis. You could simply install dielectric unions between the copper and the black pipe, but black pipe should not be used for water if that's what it is. I would get rid of it all together.


Your newest picture shows that it's not "black pipe", but appears to be galvanized pipe that's been painted black.

Either way, out with the old... in with the new.


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## oh'mike (Sep 18, 2009)

That's the goofyist looking gas line --No plumber did that-----


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## TheEplumber (Jul 20, 2010)

:thumbup:


oh'mike said:


> That's the goofyist looking gas line --No plumber did that-----


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## LateralConcepts (Jun 6, 2010)

oh'mike said:


> That's the goofyist looking gas line --No plumber did that-----


Must have been the electrician...


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## Daniel Holzman (Mar 10, 2009)

I have a similar hot water heater. I have threaded galvanized pipe coming out of the heater, with a dielectric union to copper. This has worked fine for more than five years, no corrosion. I have never seen a crimped fitting attached to a heater, always threaded, doesn't mean yours isn't crimped, just never seen it. 

Galvanized pipe is much more corrosion resistant than black iron, but you absolutely need the dielectric union to prevent corrosion, you can get them at any plumbing store on a big box store.


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## plumberinlaw (Feb 22, 2010)

NHMaster said:


> The nipples coming off the tank are perminent and can not be removed. The corrosion is because the copper female adaptors are leaking. take it apart and re-dope the fittings


this guy sounds like he has done this before


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## LateralConcepts (Jun 6, 2010)

> Galvanized pipe is much more corrosion resistant than black iron, but you absolutely need the dielectric union to prevent corrosion, you can get them at any plumbing store on a big box store.


Not sure about the cost difference, but dielectric nipples might be cheaper than dielectric unions.


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## NHMaster (Dec 21, 2009)

plumberinlaw said:


> this guy sounds like he has done this before



So do it again and this time get it right. :thumbsup:


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## boyfly (Dec 26, 2007)

Thanks for all the advice. Looks like I just need to set some time aside to tear into it and figure out exactly what I have to work with. Hopefully it will be simple enough to fix once I do take it apart so we aren't without hot water for days...


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