View Full Version : FLEXIBLE copper pipe?

11-07-2008, 06:37 PM
I'm thinking of connecting 3/4" flexible copper piping from gas HW tank to the solid copper piping above for both hot and cold. The connections will be about 1 1/2 to 2 feet long.

Provided they are not kinked when installed, has anyone had any negative experience with this type of flexible copper piping, such as leaks from the piping itself rather than the connections?

11-07-2008, 07:05 PM
These would be my choice.


11-07-2008, 07:49 PM
These would be my choice.


That is what I was thinking of using initially but a plumber I talked to suggested the flexible copper as a "better" alternative.

Any one else with pros and cons on these two? What's the consensus on here?

11-07-2008, 07:51 PM
The corrugated copper lines will make better bends than the stainless steel ones. The stainless steel flexibles will kink unless they make VERY long radius turns and that is not always possible with water heaters.

11-07-2008, 08:39 PM
I prefer the corrugated copper. They are quite reliable, and flex lines are required by code in CA.

I have experienced numerous pinhole leak failures in the braided stainless steel WH connectors. Can't explain this, because I never saw it happen on a faucet connector, but I just won't use them on WH.

master plumber mark
11-08-2008, 05:49 AM
The copper connectors are ok ....but after a time they seem to
start having a reaction like the "dia-electric" unions do..
and they develope the pin holes and cracks in the bends...
and generally flood the home out about 5-10 years down the road...

this is probably the same case with the solid steel SS connectors we tried for a while.

that SS connector posted above is ok,
but it is about like wrestling a 10 foot python to get it
to form correctly to your situation.......

the absolute best I have found for both water heaters and
water conditioners are these black braided connectors.
they have saved me tons of time in mean -- difficult installations...

I believe they also provide much, much better protection for the
water heater than just a normal dia-electric union.

how long they last I will have to wait and see..


http://onsmartpages.com/weilhammerplumbingco/nss-folder/pictures/si_UEw80h80_DSC05763.JPG (http://onsmartpages.com/weilhammerplumbingco/pictures/view_alone.nhtml?profile=pictures&UID=10216)

11-08-2008, 06:18 AM
About those black nylon braided lines....the ones I have used have some kind of black rubber lining, and after about 5 years you start getting serious black streaks in the hot water!

11-08-2008, 08:40 AM
The corrugated copper ones will normally last longer than the water heater. I am not sure if the black ones are rated for hot water, since the only place I have ever seen them used are on water softeners.

master plumber mark
11-08-2008, 08:56 AM
Yes, of course they are hot water rated...

this is what my supply house has been selling
for about 8 years now ...for both hot and cold...

the only difference between the SS corogated ones
and the black ones are the outer liner.....

the internal water line that is affected by
the water is identicle......or so I am told.

these are just more handy-dandy

I have never heard a thing about black streaks or anything else
with this brand

I think they are a much better choice than a dia-electric unioin.

they certainly insualte and isolate the heater from the rest of the system.

11-08-2008, 10:23 AM
Those flexable copper connectors sure can corrode into nothing. Last Sunday my neighbor came running over screaming that there was water all over her crawlspace.

She tried to disconnect her swamp cooler for the winter and when she shut the ball valve coming off a tee from the water main the tee broke. Keep in mind this is all 25 year old worst DIY I have ever seen.

This is a trailer house that was half assed converted into a real house, they bascially built a house around the trailer and added some sqft. The main galvanized line coming out of the ground is about 6" to the right of the line coming out of the bottom of the trailer house.

The guy put this tee on there for the swamp cooler and then used a corrugated copper pipe to connect the main line. It looked like a snake all bunched up and kinked the way he did it. Then he connected the cold water bond for the breaker box above this copper mess.

Then he wrapped the whole thing super tight with fiberglass insulation and a roll of electrical tape. When I took the soggy insulation off it was one giant rusty corroded mess. Gee I wonder why the galvanized tee broke off the nipple?

11-08-2008, 07:43 PM
25 years?
I'd be happy if the corrugated copper connections (or any connectors for that matter) lasted half that time.

The heaters I'm getting have factory installed true dielectric fittings to which these corrugated copper connections will be attached.

I know the corrugated copper connectors crack VERY easily if kinked, that's why I was considering the braided SS connectors.

Do the above 3 types of connectors have different PSI ratings?

11-08-2008, 10:53 PM
Like hj, for me, the copper flex supplies seem to last as long as the heater.
If I ever remove a flex, I replace it.
I never reuse an old one.

11-09-2008, 06:48 AM
Do not even try to equate that mess with a copper flex connector on a water heater. If it was kinked that by itself would have shortened its life, and the other conditions have no bearing on how they are used with a water heater. Plus, from what I read it was the tee that failed, not the flexible copper connection, and it does not seem to have "corroded away to nothing".

11-09-2008, 10:40 AM
I did not explain that well, the nipple going into the tee broke off in the tee. All the plumbing is a terrible mess in her house, along with everything else. I repaired the line with PVC. I told her she really needs to get a plumber out there to look at the whole thing.

The other thing that really worried me was that the water line going to the well has heat tape on it. It appears he was too lazy to dig below the frost line and just buried the pipe a few inches below the surface.

She said she plugs that heat tape in when it gets real cold. Then I looked up and saw the outlet she plugs it into :eek:. It is just an outlet with some old extension cord feeding it, no box!! I wonder where the cord goes, nah I don't want to know.

01-06-2009, 06:11 PM
I have a 6 year old GE Gas Water Heater which I installed dielectric connectors. The water heater is warrenteed for 12 years. When I installed an expansion tank on the cold water side I had to disconnect the line and noticed a huge amount of corrosion at the connector. It appeared that the connector corroded closing the 3/4 inch opening about 1/2 of the way.

The hot water side was no better.

I took off the old dielectric connectors and installed stainless braided connectors. The same ones displayed in this thread. Everything looked great but the connectors at the water heater side kept leaking. Not a lot but enough to be annoying. I tried reconnecting with more teflon tape. Tried Teflon tape and pipe joint compound, etc, etc.. Nothing worked.

I then replaced the stainless connectors with flexible copper and it seems to have solved the problem. The connector on the flexible copper are deeper with more threads and the washer is thicker and slightly tapered which may be making the difference.

I live in NY so I don't have movement issues but if the flexible copper fails, does it fail in a catastrophic way or does it leak and give you a chance to replace them?

They also say not to overtighten the connector. I'm assuming that's because you can crack the plastic insulator?

Any comments?


Gary Swart
01-06-2009, 09:34 PM
I always use the copper. The supply house where I get my heaters supply them and they work just fine. Certainly use care not to kink them. The come in various lengths so get them just a tad longer than necessary and you won't have a problem.

01-06-2009, 10:06 PM
I prefer to use the brasscraft black braided water heater connectors, and I have yet to experience any problems with them. On the other hand, I have heard nothing but bad things about the copper connectors, and I don't think the two suppliers I visit even carry them anymore.

01-07-2009, 06:15 AM
And my supplier has never even heard of the black plastic connectors, so it is an individual thing.