DIY Plumber
New Member
When I turn on my water taps first time in the morning they put out a little psst of some gas (no smell). We are in the LA area. Our water comes from the Metropolitan Water District and has been disinfected with chloramine for at least ten years. This psst problem has been going on for several months and during that same approx. period we've had two pinhole leaks, with the last one wasting about $100 of water - it was in the crawl space and we only found it after we got an enormous water bill.
I'm thoroughly familiar with the big house-rattling belches of air you get when you turn on a tap after a water line has been disconnected and then re-pressurized. What I'm talking about here is a small amount of some gas, maybe just a few ccs, the first time I turn on the tap - hot or cold - in the morning. A psst, not a belch. And it is every day.
I have it in two houses, both in the same neighborhood. Both have copper re-pipes, one done in the late 1970's and the other in the late 1980's. I have also noticed it in a local hospital building which is from the early 1980's. But I don't know what kind of pipe was used there.
I recall an explanation that when copper pipes are disinfected by old fashioned chlorination, a protective layer of something forms, maybe a biofilm or a tightly clinging oxide, and then when the water is changed to chloramines the chloramines gradually clean off the protective layer. And then once the pipe is no longer protected by the former layer, the oxygens in the water react with the copper producing an unstable oxide (one that washes away) allowing the eventual hole. (From boating I know that the formation of stable oxides is what keeps stainless steel from corroding, even underwater, except when something is rubbing against the ss removing the protective oxide AND there is no oxygen available to remake the protective oxide because the water is stagnant, with no oxygen dissolved in it.) Thus I suspect that the little spurts of gas I've been noticing are hydrogen, what's left of some former water molecules.
Anyone else having the psst problem? (Please take the time to read the entire post above, before you reply.)
I'm thoroughly familiar with the big house-rattling belches of air you get when you turn on a tap after a water line has been disconnected and then re-pressurized. What I'm talking about here is a small amount of some gas, maybe just a few ccs, the first time I turn on the tap - hot or cold - in the morning. A psst, not a belch. And it is every day.
I have it in two houses, both in the same neighborhood. Both have copper re-pipes, one done in the late 1970's and the other in the late 1980's. I have also noticed it in a local hospital building which is from the early 1980's. But I don't know what kind of pipe was used there.
I recall an explanation that when copper pipes are disinfected by old fashioned chlorination, a protective layer of something forms, maybe a biofilm or a tightly clinging oxide, and then when the water is changed to chloramines the chloramines gradually clean off the protective layer. And then once the pipe is no longer protected by the former layer, the oxygens in the water react with the copper producing an unstable oxide (one that washes away) allowing the eventual hole. (From boating I know that the formation of stable oxides is what keeps stainless steel from corroding, even underwater, except when something is rubbing against the ss removing the protective oxide AND there is no oxygen available to remake the protective oxide because the water is stagnant, with no oxygen dissolved in it.) Thus I suspect that the little spurts of gas I've been noticing are hydrogen, what's left of some former water molecules.
Anyone else having the psst problem? (Please take the time to read the entire post above, before you reply.)
