Hello.

I moved into this house about 8 years ago and had two pinhole leaks at the start. A plumber said dissimilar metals on the pipes caused it as two of the leaks occurred where galvanized strapping and electrical wire casing made contact. So I found anywhere metal of any kind was making contact with pipes and removed it.
Problem solved I thought.

Over the next year or so, more pinhole leaks. The leaks occur with white sometimes yellowish mineral deposits mostly on exterior of pipe or valve. Inside the damaged sections of pipe was crystals, blue and green. (pics below). Both hot and cold lines affected.
I figured pipes were 40-60 years old so replacing some would put me on the right track. So I replaced a lot of valves and runs in the basement. Also did a remodel in basement bathroom and the kitchen so I did repipe into the ground floor. I also turned down water heater temperature. Now problem solved…

Now its about 4 years later and all the beautiful new copper and remaining old pipe is corroding - same mineral deposits on the exterior of pipe and valves. (see pics below)

I have asked the water authority to come look. They said they will take a sample and test it.

I put a multimeter to the pipe near the basement water main. I am not an electrician and I am not sure the meter is working right but I got .027 AC volts. And the DC volt reading just floated up and down which I don’t understand. I think I identified the copper wire that grounds the piping to the house earth ground but I don’t want to poke around in the circuit panel. The ground wire to the buried water main looks intact but Im not a plumber either.

I am trying to understand what is causing this and what the solution is? I worry it will be repiping the whole house. I certainly can’t do that every 4 years. If anyone can offer any idea or opinion on this I would be greatful.

Pics:
[postimg.cc]
[postimg.cc]
[postimg.cc]
[postimg.cc]
[postimg.cc]
[postimg.cc]
[postimg.cc]
[postimg.cc]
[postimg.cc]



Edited 1 times.

Sounds like pit corrosion to me. heres a video explaining.

[www.youtube.com]

If you have a circulating pump on your copper system, you can also get pitting and erosion caused by turbulance of water at short turn elbows especially near the pump.

That should not cause the problem with the cold water, however. Nor in straight sections of pipe away from the turns.



Edited 1 times.

thanks for that video. I can see the corrosion spot they showed in the shop is like the one in my photo of the long pipe. is it right to figure it is not flux since leaks are on the hot side too?

I did get a new water heater in 2018 and the sacrificial anode rod in the old tank was in decent shape I recall. so I figure I dont have iron particles coming from the tank like in the video.

when the recent copper was installed I saw the plumber reaming the pieces so I dont think it is from burrs.

hot water out of the gate is a nice idea but no, never had a circulating pump here.

new info.

had a plumber here. thinks the cause is the dissimilar metals from before. said it doesn't matter I removed the bad metal off the pipes four or so years back, the corrosion will keep going. he wants to replace all the supply sends in basement w PEX but leave the copper branches up to the ground floor bathroom kitchen in place.

I dont understand how more leaks form if the dissimilar metals were no longer in contact with the copper? Maybe I should get a second opinion on that.

I also was told the water authority dropped the ball for the last few years with water chemistry and a lot of people had to replace their pipes like me. The plumber confirmed he had seen and replaced a lot of pipe in this service area like my situation.

in either case wouldn't it be best to replace all the pipe w PEX? otherwise why won't I just get more leaks later from remaining copper to bathrooms/kitchn?

if you repipe then REPIPE


ALL OF IT


open the walls as necessary


it will NOT be cheap if done PROPERLY by a licensed, bonded, insured plumber AND a building permit


BUT


"Pay me now, or pay me much much more LATER."


paying now not only minimizes the total 'down the road' cost BUT avoids all the future aggravation

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638