We have a 5-year old home with a gas water heater. There is a lot of corrosive-looking material (rust colored flaky stuff ) where the 3/4" copper house plumbing is connected to 2 steel or some other metal (not copper) pipes coming out of the water heater.

I'm not sure that is very clear. In other words, there are two pipes coming out of the water heater that are made of some metal other than copper. They are about 8" long or so. The 3/4" copper cold water supply is connected to one of them with a threaded fitting. On the outlet side, another 3/4" copper line (house supply hot water) is threaded to the other pipe coming out of the water heater.

I'm assuming the two metals do not agree with one another and that is causing the corrosion.

Assuming that is correct, is this just a simple matter of removing the dissimilar metal pipes and replacing them with copper? There are no shut-offs plumbed in either so I would want to add those. Would 1/4 turn valves be appropriate?

Thanks for any advice.

massplumber2008

Hey Augy:

I see these guys have been helping you. Great information, as usual!!

I can tell it is type M (thin walled) copper tubing in the first pic. because the copper tube has a RED stripe...that red stripe tells me it is type M copper tubing (Typle L copper tube is blue line).

I would be able to save that tee, but do yourself a favor and get a new 3/4" copper tee AND a 3/4" copper coupling in case you can't. The trick on this is to clean the old fitting and shutoff, flux it up, then heat middle to top of valve (primarily middle) and then when solder starts to pop a little, twist and pull down and off. Then reheat the joint a little more and wipe the joint clean. Sandpaper this joint when cooled, flux it and then solder a new 3/4" copper BALLVALVE in place. If that doesn't play out for you...just cut the tee out, attach couplings, new tee and new shutoff.

From there, well...depends on what you do. The corrugated flex lines Ballenger and KISS suggested work great, allow flexibility and allow for easier installation of the NEXT water heater..

Still need to solder at a spot or two though. ALL fittings that are to be soldered and then teflon taped must be PRESOLDERED onto copper tube (and cooled) BEFORE applying pipe dope or teflon taping anything.

Depending on which flexi. you go with..will need 3/4" copper male adapters and those 3/4" dielectric nipples (see pic)...these are short and help reduce the electrolytic effect between nipples and tank tappings.

In terms of soldering...YUP!! Kiss said it..I like MAPPGAS system...burns super hot (propane or acetylene)....AND when I have apprentices solder for me I ask them to do the following:

Shut off main water shutoff to the house. Open all faucets in the house and the outside faucets as well. If laundry tub in basement open faucets there, too (may even need to diconnect washing machine hoses and drain those, too. Then you will need to drain 5 gallons or so of water from the water heater so water is well below where you will be soldering...Then, only then, can you solder (if any water is issue after this, then main shutoff may not be working and you may ned to unhook your water meter and let drip from there while soldering).

After complete job, turn off all faucets, reconnect all,, and then turn on water main...NOW, fill the water heater and then go to laundry tub and open faucet to bleed system..then next, open the TUB upstairs, and continue to purge air/sediment from the lines up there (no aerators here, so less chance of clogging faucets). Once tub runs clear can start to purge other faucets of air/sediment and should be all set to go!!

*Whew*..you think you went off track...huh??

If you have any other concerns...let us know. One of us will follow up with you soon!! Good luck...Mark


If this helped please RATE THIS ANSWER. Thank you.

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Augy123

Ok, I have seen those before. One end sweats to the copper pipe and the other threads onto the nipple? That looks pretty simple. I'll try to pick this stuff up this week and get it installed. I'll post back with the results. Thanks.

Augy123

massplumber2008, thank you for the reply. I will certainly buy plenty of parts and plan to return what I don't end up using Good info there...thanks.

Anyway, I stopped over lunch and had a good look at what's available at the chain stores. I then came home and really looked over what I need to complete.

I just have a few questions left (I promise...then I'll just get on with it!)...

HD sells compression-type fittings called Shark Bite (I'm sure you're familiar with these). In lieu of sweating fittings, could I use the Shark Bite Fittings? They are pricey so it might be smarter to buy a new Mappgas soldering kit...thoughts?

Also, a 10' length of Type L 3/4" copper is the shortest they sell and it's $34!!! I need about a foot! They have 5' pieces of Type M but from what I understand I don't want to use that...correct?

Using Shark Bite...could I use PEX tubing rather than copper or is that inviting trouble?

The chain stores all sell the corrugated steel and/or copper flex hoses (finally found them with the water heaters). They also sell braided stainless steel hoses that say they are for water heaters. These are more flexible but are they a good option?

Lastly (I think)...the shortest lengths of the flex connectors is about 12". I only need about 8". I'm afraid the 12" or 15" connector would be overly stressed to fit in that space. So, I figure I'll just cut out more of the house 3/4" copper pipe. The only other idea I could come up with was to put an elbow about 8" above the W/H and use long (24" or so) flex connectors and kind of loop them up and around to make this connection. Does that make sense?

Again, thank you all for your help. I'm really sorry for all the questions....just want to get this done right the first time.

KeepItSimpleStupid

I'll take a couple of them:

Look for the copper tubing at a mom and pop hardware store. I have a true Value nearby and they sell shorter lengths.

One thing that you may have overlooked is the use of couplings and unions.

Couplings

They come in two varities:
1) With a stop in the center (could just be a dot)
2) Without (For putting pipe together)

Unions

It can be used and it offers the option of easily fixing the pipe fittings if they leak. On the negative side, you would have to use two and most likely temporarily remove the gas line.

In any event, I see you having to so the following:

1. turn off the water heater
2. Turn off the main water supply
3. Drain the cold and hot water lines
4. Drain the hot water lines
5. Drain some of the hot water out of the tank from the bottom.

6. Cut the inlet and outlet in two places or cut in one and move the water heater slightly.
This may involve shutting off the gas to the house or the appliance. Pay attentntion to lengths.

7. Remove shut off valve.

8. Install shutoff valve with a new piece of pipe and a short extension of pipe.

9. attach temporarily and measure the length of pipe required to the valve.

10 Cut.

11. Teflon tape the Female adapter and dialectric nipple finger tight + 2 turns. Use only two wraps of tape and dont tape the first thread. Tape in the direction of tighten.

12. Put the coupling on without the dent.

13. Do essentially the same process on the outlet without the valve and don't forget the coupling.

14. Move the pipes in place.

15. Mark where the coupling goes and add about 1/2" to each side.

16. Move the water heater in place.

17. Put something to hold the coupling in place like a vise grip.

18. Solder. and hope you don't have a leak at the water heater.

You can use a union rather than a coupling if your scared. You can then take it apart again if it leaks.

You MUST NOT solder close to the water heater because of the plastic linings.

Maybe not quite right, but I hope you have the idea.

9.

Augy123

Thanks KISS, I would plan to use couplings if I sweat this all together. I'm just wondering if those shark bite fittings and some PEX tubing would work and be a reliable solution. That would allow me a lot more flexibility in aligning everything (and save me a lot of sweating headaches using my propane torch and (apparently) less-than-stellar sweating skills!).

Regardless, I plan to install the short dielectric nipples to the tank, then use the flex hoses (still curious if corrugated steel vs corrugated copper vs braided makes much difference) to connect the nipples to the hard plumbing with male fittings either sweated or compression-fitted to the 3/4" copper house pipe.

In the end, I want to do what is best so whatever you guys say is the way to go I will heed your advice.

KeepItSimpleStupid

Steel and braided are not the same material as copper, so corrugated copper probably makes the most sense.

The sentence fragment enclosed in []. You connect nipples (male) to a "3/4 sweat female adapter".

I hate compression fittings.

ballengerb1

"and/or copper flex hoses (finally found them with the water " that was the pipe I refered to many posts ago. It may be the best opion if you don't like to sewat pipe.

Augy123

Sorry guys, I'm probably making this an unreasonablly long thread. I'll just grin and bear it and sweat the proper fittings. Sounds like the sharkbite fittings aren't a good solution.

Augy123

I am having trouble removing the nipples. I started with the hot side and cut the copper off. I'm trying to remove the nipple and it won't budge. I'm afraid I might damage the w/h where the nipple threads in if I pry too hard.

Any suggestions. Thanks.

KeepItSimpleStupid

"Pry"? Corrosion is nasty stuff. Remove as much of the rust as possible at the fitting with a small wire brush. Wd-40 can help. A pipe wrench will give you a grip to turn.
If you have to, turn slightly in both directions