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Water connections for new water heater

42K views 16 replies 6 participants last post by  Ultrarunner2017 
#1 ·
I'm installing a new water heater and believe the connections I laid out in the picture would be appropriate, but I'm not entirely sure. Also the copper water supply in my basement is 1/2" - previous owners hack job is a sight to see. Converting it to 3/4" is a future project - I'm just prepping the new water heater for that PEX? conversion.

From the water heater COLD side I was going to install a copper 3/4" female adapter, 3/4" pipe, 3/4" male adapter, 3/4" ball valve, 3/4" m x 1/2" adapter, 1/2" pipe, 1/2" brass compression union, to 1/2" copper water supply.

From the water heater HOT side I was going to install a copper 3/4" female adapter, 3/4" pipe, 3/4" x 1/2" adapter, 1/2" pipe, 1/2" brass compression union, to 1/2" copper water supply.

The compression unions came with brass sleeves. It's my understanding I don't need to use them when connecting to copper - that they are used to prevent twisting when connecting to PVC etc. Is that correct?

Would having the brass compression unions suffice if there ever was a need to service or remove the water heater? Is there a better way?

It looks like galvanized pipe connections on top of the new water heater. I thought I remember hearing the need for a union when you connect different pipe materials. Can I connect 3/4" copper to that or do I need to install a union to convert to copper like my old installation does (see picture) ?

Is tape recommended for copper threads?

Any suggestions are appreciated, thanks.
 

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#3 ·
The unions on the old installation are dielectric unions. They facilitate taking everything apart as Bob said but they are also used to separate dissimilar metals to combat electrolysis. Furthermore, use of dielectric unions on a metallic plumbing system that is used as a grounding electrode (most are, as required by code) requires that you install an 8 gauge bonding jumper from hot to cold above the unions so continuity isn't lost at the water heater. The bonding jumper is not needed with dielectric nipples as metallic contact is not lost.

Unless the convenience of a union is needed, I wouldn't use them. The nipples that are in the top of the new water heater are dielectric nipples (see the blue plastic liner?) and you can connect copper straight to them.

I can't tell what you've got in the Watts packages at the top of the picture.

Can you solder? If so, you can ditch most of those fittings and make this easier. If not, consider using SharkBite fittings and/or flexible water heater supply lines. The flex lines make for an easier install.

Yes, use teflon tape on the threaded connections. It'll take about 5 wraps of tape on the 3/4" nipples.
 
#12 · (Edited)
Can you solder? If so, you can ditch most of those fittings and make this easier. If not, consider using SharkBite fittings and/or flexible water heater supply lines. The flex lines make for an easier install.
I can sweat solder. How would I ditch most of the fittings and make it easier?
(My current adapter layout is in a picture above.)For my own sanity, I'm heading toward solid copper rather than a flex water whip. No offense anyone. A plumber told me the water whips sure are convenient and get the job done in a pinch, but they will wear and ultimately fail due to water pressure on the corrogated ribs. "They'll sell you anything" was his comment. I don't want to be away from home when that happens.
 
#7 ·
thekctermite - excellent info on dielectric unions and nipples, thanks. I didn't realize those were liners in the dielectric nipples; I thought they were shipping plugs at first glance when opening the box.

The Watts packages are 5/8" OD brass compression unions (picture) that I was thinking of using as a quick connect to the 1/2" copper water supply and disconnect if the heater ever had to be moved. By the way, these come with brass insert tubes and I'm under the impression I don't need them for copper connections, that they are mainly to stabalize pvc connections from twisting. I would still use the sleeves and nut. Is that correct?

I can sweat solder and have the supplies. What do you suggest to make this easier? The only thing I could think of was swapping out the 3/4" ball valve to one with sweat connections. The setup in the picture runs about $25. Replacing the existing plumbing with PEX would be a future job if we end up staying in this house.

I can check into the cost of a sharkbite setup. I'm just not sure what I would need or have a ballpark idea what it would cost. I seem to remember seeing the watts quick connectors were about $10 each. Ideas?
 

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#9 ·
I can see your point about using a flexible whip connector. Isn't there a requirement to have a water supply shut-off valve? If so what's the best setup for that in conjunction with the whip?

I imagine I would run the flex from the heaer to a ball valve connected to the 1/2" water supply. 12" is roughly the legth needed. I'll have to look for a shorter length of flex since I've only seen the longer ones.
 
#13 · (Edited)
From the water heater COLD side I was going to install a copper 3/4" female adapter, 3/4" pipe, 3/4" male adapter, 3/4" ball valve, 3/4" m x 1/2" adapter, 1/2" pipe, 1/2" brass compression union, to 1/2" copper water supply.

From the water heater HOT side I was going to install a copper 3/4" female adapter, 3/4" pipe, 3/4" x 1/2" adapter, 1/2" pipe, 1/2" brass compression union, to 1/2" copper water supply.
For the cold, sweat on a 3/4" threaded adapter to a short length on 3/4" pipe, do this on the bench. Allow to cool, wrap the threads of the dielectric nipple with telfon and install the apapter and pipe to the tank. Dry fit a 3/4" ball valve, another short length of 3/4" pipe and a 3/4"-1/2" reducer. Sweat these in.

For the hot, same as cold, minus the shut off.

Added: Cut out all of the old copper unions/couplers and get back to solid pipe
 
#17 ·
I realize this thread is a bit aged, but since it's right along the lines I will have to follow in the (hopefully distant) future when I replace my 10yr old water heater, it helps to get the info/advice before hand.

Currently, mine looks like a hack job. It's 1/2" going into the heater, right up to what I now realize are dielectric nipples.
The reason I came here was to find out whether there was a reason the previous install used these galvanized nipples, and found that they were the dielectric that are apparently supplied with the WH.

I have 1/2" unions on both the hot and cold, and will be upgrading to 3/4" on the eventual new install, since I already replaced the mains coming up to the mess with 3/4" copper.

I kind of thought the unions were absolutely necessary to make eventual replacement easier, but now that I have done a lot of copper sweat, I realize that it's just as easy to cut the old pipe and sweat in the new.
Just have to be sure never to sweat close to the WH.

One thing that complicates my situation is that there are T's for supply to the bathroom, and the furnace close to the WH, but I can reconfigure it to make it easier.

As far as the gas connection to the WH, is it OK to use a flexible connection, or does it have to be pipe?

I hope that I won't need this info for a while, but I'm thinking of pre-assembling most of the new install so that when (not if) the time comes, I'll be able to buy the water heater, call the inspector, and have the job done and ready for him to inspect by afternoon same day.

Thanks

Fw
 
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