I need help solving a residential plumbing problem.

[Calvin344]

Hi, New member here. I have searched the site to see if my ? has already been adressed but only found 1 post about "black stuff' and it didn't seem to be related.

Here is my situation. Residential plumbing in a home with 3&1/2 baths-two story-42 years old. For appx. 3 years now I have had "black stuff" come out of the upstairs shower hot water side and in just the one shower. I have sought the advice of the water company who have had reps come out & checked their end including the o-ring where my line connects to the meter. They say it is not in their water. This debris comes out for a few seconds and has an oily look to it. It is greasy as it clings to the tub. It kind of spiderwebs in the water and looks like distorted snowflakes. I provided a sample to the water co. and they refused it. I actually think it is something in my house. This seems to occur with almost monthly regularity. Knowing what chlorine does to black rubber-
I have changed everything rubber in the entire house right down to the gasket between tank & commodes. Yes- Faucets everything. Water heater was drained & then I just bought a new one as I thought maybe impurities were clinging to the anode rod. ( I have talked to plumbers & had plumbers out but no one has told me they can actually fix it short of re-plumbing the entire house.) It still persists.
So finally an older plumber told me my house may have an expansion chamber built in it as that is the way homes were done when it was built. What ever reason or how it was built, this was the most logical explanation I had heard to date. He also told me there is no way to get the stagnant water out as there needs to be an air inlet to allow this water out of the expansion section. You MP's know about all this I am sure. He explained how pipes "bang" and this expansion had air in it and created a buffer to keep the pipes quiet. He said- In the highest point of my house and at the end of the run is where the expansion pipe or what ever would be located. He said over time the air seeps past the water or vice versa and the expansion becomes filled with water which stagnates and finally lets loose when there is too much in the pipe. creating the "black stuff" which is stagnant water. It sounds good, he recommended a "minirestor" TM device I guess. I went to Lowe's and looked at them, talked with the sales person and looked them up on line but I don't know if that is the fix.

Finally- I will get to my specific questions. (sorry for the length) (1) The mini restor sounds to me like it is a fix for a single sink, or toilet, or washing machine- not a "fix all" for the entire house. (2) Do I have to go upstairs and start cutting holes in the walls to find this expansion chamber? Is there any way to know with some certianty where it is? Is there actually one there? (I don't want to tear the house apart for no reason) (3) If I do find it how do I fix it? Shut the water off, cut out the section and let it drain then replace it patching the hole in the wall behind me? (4) Is it worth trying to- Shut the water off to the residence, open all the faucets, drain and open the water heater so that everything drains out? Won't the water in fact drain out or will there be enough suction in the expansion chamber to hold the stagnant water in as the plumber told me? (5) And- If the expansion chamber is full- why don't the pipes bang as it must be rendered useless with the water backed up in it?
Sorry for the length of this post but I wanted to include as much info as I could. Any help would be greatly appreciated. Thank You and all of you MP's for this forum. Cal

 

[Jadnashua]

You could have an actual expansion tank. These are normally installed in the cold water line near the water heater. They are generally installed to account for expansion of the water as the heater raises the temp (the water expands). If you have a closed system (i.e., either a check valve or prv) in the house, they are required. The water in it genrally isn't stagnent, as long as the bladder is intact. Old-school thoughts to water hammer had a stub of pipe rise before the fitting to the valve. The theory was that they would hold air, and allow the moving stream of water a place to go when you shut off the valve, preventing hammering of the water column against the now closed port. Those never worked for long, as the air got absorbed in the water and they ended up full. Trying to empty them by turning off the water and draining the lines was akin to holding your finger over the end of a straw...it just plain doesn't work. So, once full, they stayed that way. Thus, the advent of engineered arrestors. Keep in mind that you normally only need a hammer arrestor for quick acting valves like on the washing machine, ice makers, and dishwashers. A typical valve doesn't require one. If the pipes are well supported, even if you have a water hammer, it may not move the pipes enough to bang into something whereas you'd hear it. It can take its toll on internal bits, like washing machine hoses, toilet filler hoses, and sink faucet supply lines, (since those are the most flexible and likely to move), but you may never notice.

Some flexible water heater supply pipes could have some rubber in them that creates the problem, but you'd normally see it at all hot outlets, not just one.

None of this answered your question, sorry, but might have given you some background info. You could probably pay a lab to determine if the black stuff was organic (growing) or some breakdown product from a component.

 

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[NHmaster3015]

Before you start hacking holes in the walls and such, take a look in the toilet tanks and see if there is any of that black slime in there. If so, get back to me.

 

[Calvin344]

Thanks for the speedy replies.

Any, info is appreciated.

The water heater is in the garage and no expansion tank that I can see. I don't think there would be room even in a "wet" wall for one would there? So I am guessing no tank.

I did go and check the three tanks and no slime is there. Along with everything else I changed all the flush valves about 1 year ago, again this has been going on 3 years.

I even thought a previous owner may have done a quick fix on a broken copper pipe with something like automobile heater hose but crawling around under the house and anywhere else I could see- I saw no such thing. I think if that had been the case I would have had a leak by now so I kind of ruled that out.

Do you think it is in fact an expansion chamber problem?

Wally- you mentioned the black slime. Could that be waste water you are thinking about. If so is it possible the fresh water and waste could migrate back & forth as they are separate systems? (I mention this because in racking my brain I wonder about ANY and EVERY thing.)