Question about hot water recirculation in a relatively large home
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I have no reason to drink cooled hot water. 
Please don't rush the inevitable. 
RE: suggestion to run cold water for 30 sec to flush out "stale" water, e.g. overnight. Does flushing a toilet count in this case? Or still need to run kitchen faucet for 30 sec before filling up my water filtration pitchers. Wondering what those of you who observe this would do.
If you are seriously asking this question, the answer is it depends on your piping layout. The intent of running the water for 30 seconds is to flush out the "stale water" that is in the line to your faucet. And actually, how long to run your water would also depend on your piping layout.
But if you are asking in jest, LOL!
Any article that has concerns about copper, stainless steel, and plastic existing in your water piping loses all credibility IMHO. My wife cooks in stainless steel and copper. Candy is made in copper pans. Beer is made in large copper vessels. The vast majority of the houses in America have copper piping, and the recent move is to plastics.
And while this article is concerned about these "modern" materials of construction, there are still ~20 million Americans drinking and cooking with water from lead service lines. My brothers-in-law's former house in south St. Louis had lead pipe supply lines throughout his house. As a side note, there is nothing more beautiful than a lead pipe "wiped joint".
But if you are asking in jest, LOL!
Any article that has concerns about copper, stainless steel, and plastic existing in your water piping loses all credibility IMHO. My wife cooks in stainless steel and copper. Candy is made in copper pans. Beer is made in large copper vessels. The vast majority of the houses in America have copper piping, and the recent move is to plastics.
And while this article is concerned about these "modern" materials of construction, there are still ~20 million Americans drinking and cooking with water from lead service lines. My brothers-in-law's former house in south St. Louis had lead pipe supply lines throughout his house. As a side note, there is nothing more beautiful than a lead pipe "wiped joint".
Is the article you’re talking about the article you found and linked ?
Lead in drinking water isn’t a real problem because your brother in law had a house with lead pipe ?
Yes, to the first question.Is the article you’re talking about the article you found and linked ?
Lead in drinking water isn’t a real problem because your brother in law had a house with lead pipe ?
"Lead in drinking water isn’t a real problem?????????"
What I said Twowaxhack was, "...while this article is concerned about these "modern" materials of construction, there are still ~20 million Americans drinking and cooking with water from lead service lines."
Point being that this article is concerned about copper, stainless steel, and plastic that isn't really an issue IMHO, but that ~20 million Americans are still serviced through lead piping that is DEFINETLY a problem.
Where did you get, I thought, "Lead in drinking water isn’t a real problem because your brother-in-law had a house with lead pipe?" ?????
Point being that this article is concerned about copper, stainless steel, and plastic that isn't really an issue IMHO, but that ~20 million Americans are still serviced through lead piping that is DEFINETLY a problem.
Where did you get, I thought, "Lead in drinking water isn’t a real problem because your brother-in-law had a house with lead pipe?" ?????
most great cooks love copper vessels for cooking. The top of line cookware is
Great Chefs prefer copper and SS. My wife has collection of All-Clad SS. It has a copper core. She would be very upset if someone tried to take it. Don’t cook in aluminum.. cast iron for cornbread. Can’t beat it!
Here are my points.
You’re criticizing an article that you found and posted for its content.
Then you tell us about your brother in laws former house that had lead pipes like that’s suppose to support your position.
Lead is a problem and hot water makes the problem worse. Remember the subject ? Heated water sitting in pipes then being pushed into the cold supply.
Thank you for reading.
Serious question. No idea about the water in the pipes so probably best for me to still run at the faucet for decent time in the morning even if all the toilets are flushed. I do appreciate the article you linked to.
Personally I wouldn’t drink the previously heated water. I’d only drink filtered water and usually never from a plumbing tap. I buy my drinking water for the taste.
I’ve found a lot of things in drinking water from a public utility so I will not drink it except when I have to, and that’s rare to never.
Still a little confused about your response.
Yes, I criticized an article that talked about the concerns of water systems that had copper, stainless steel, and plastic components. Since you are taking a stand counter to mine, my assumption is that you share the concern of water systems that have copper, stainless steel, and plastic in them. Are you going to stop installing copper, stainless steel, and plastic components, or at least tell your customers that there are health issue using them?
I did not use my brother-in-law's house to "support" my position. The point I made is in the first sentence of that paragraph; "And while this article is concerned about these "modern" materials of construction, there are still ~20 million Americans drinking and cooking with water from lead service lines." Note that "service lines" are from the mains to houses. I only mentioned my brother-in-law's house to indicate my first-hand knowledge of existing houses that still have lead pipe water systems.
The original subject of this thread was about adding a bypass valve at a second location. It then evolved into the safety aspect of drinking water from a hot water heater.
Yes, heated water increases the ability of water to leach materials from the piping in which it flows. But to flush the water, hot or cold as the article indicates should be done, because it is stale for sitting in the piping for several hours seems a bit much, don't you think? One reason for these circulating systems is to save water. However, flushing the lines before using water to drink or cook would waste a vast amount of water. And what about the cold water coming out of my refrigerator to drink, and the ice made with "stale" water that has come from my water heater via the recirculation system?
I have seen NO empirical data to support the theory used to develop this article, nor the concerns over drinking and cooking with water that has spent time in the water heater. And as the plumbing world continues to use copper and plastic, until these un-named "experts" can bring actual data to the table instead of only theory, I remain skeptical.
I'm going to go get some ice and cold water from refrigerator now.
TL/DR
The article talks specifically about lead in drinking water.
So why would you bring up 20 million Americans drinking from lead pipes. You’re insinuating that the article didn’t talk about lead.
Yes, the article says that lead is bad.
That’s all I have to say about your posts. You’re welcome to the last word.
The article talks specifically about lead in drinking water.
So why would you bring up 20 million Americans drinking from lead pipes. You’re insinuating that the article didn’t talk about lead.
Yes, the article says that lead is bad.
That’s all I have to say about your posts. You’re welcome to the last word.
OK, last word.
In no way did I insinuate the article did not talk about lead. What I said outright was that the article was concerned about leaching from copper, stainless steel, and plastics in house water systems; i.e. "modern" materials of construction. IMHO, I would be more concerned about the ~20 million Americans who are drinking and cooking with water that is definitely more likely to have health issues with water supplied to them through actual lead pipes (99.97% Pb) than any lead that will end up leaching from copper pipe (<0.05% Pb).
In no way did I insinuate the article did not talk about lead. What I said outright was that the article was concerned about leaching from copper, stainless steel, and plastics in house water systems; i.e. "modern" materials of construction. IMHO, I would be more concerned about the ~20 million Americans who are drinking and cooking with water that is definitely more likely to have health issues with water supplied to them through actual lead pipes (99.97% Pb) than any lead that will end up leaching from copper pipe (<0.05% Pb).
I'm guessing the 1.5L's of Vodka, Bourbon & red wine, I consume monthly, will do me (and my liver) in well before the trace elements from my water system do 
Plus, I'm with @havasu on having drunk from the hose, for the better part of my youth!
Also, I have no data (whatsoever) to back this up BUT I "think" our water system has had to contributed to our overall immunity levels over the last hundred plus years (or so). You would think that, ingesting those minute amounts of elements, bacteria, etc. over time has allowed our bodies to built up defenses against things we may never know about (and or killed the "less-fit" of us)!?!?
Plus, I'm with @havasu on having drunk from the hose, for the better part of my youth!
Also, I have no data (whatsoever) to back this up BUT I "think" our water system has had to contributed to our overall immunity levels over the last hundred plus years (or so). You would think that, ingesting those minute amounts of elements, bacteria, etc. over time has allowed our bodies to built up defenses against things we may never know about (and or killed the "less-fit" of us
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Previously in this thread I’d expressed surprise at the suggestion that hot water should not be consumed and received responses prompting me to search out information.
My comments are in the context of someone that grew up frequently drinking water from a garden hose (lived in CA and it got hot playing outdoors). I have never lived in an ‘older’ home and generally never considered lead paint or solder as having been used in construction.
I have upgraded the water supplies of most of the homes that I’ve occupied as an adult – larger capacity, faster recovery water heater, filtration systems, water softening, recirculation, mixing valves, etc. I all of this I’ve never seen a warning about consuming heated water – this seems odd given the often ridiculous warning labels found these days.
I find myself somewhat skeptical of the information I’ve found – at least in my context of concern.
1 – hot water leaches lead out of pipes and fittings more than cold water – I can see this as a concern if unsure of construction. This doesn’t apply to me.
2 – hot water may be more prone to contamination because there are more components – I have trouble buying into this as once a system is constructed and flushed it is then sealed. This concern would seem to apply to longer pipe runs with more fittings as equally other sealed paths. This would seem to also apply to refrigerators with water and ice makers.
3 – For the last 20 years I have kept the water heater at 140-150 degrees. If I read sources correctly, water stored at this temperature should be safer from bacteria than unheated water (it also extends the availability of bath/shower water). I use mixing valves so the water is delivered to faucets/baths/showers at 115-120 degrees.
4 – I’m going to discount the potential leaching of compounds from PEX lines as I generally do from plastic water bottles and such – I just don’t see the normal volume of usage and/or the delta of such leaching between hot/cold water as reaching a level of concern. Most of the water I consume is from my refrigerator (combination of ice and cooled water) – this would seem to have a concern similar to #2 in that it puts more components in the chain from source to consumption??
5 – The time and temperature of water sitting in pipes can contribute to bacteria growth – lukewarm water over longer periods of time is conducive to bacteria. This applies equally to hot water cooling off and cold water warming up as it sits in pipes. Some sources suggest that any water sitting in pipes for 4+ hours is suspect and should be flushed. Many flushing suggestions specify 30 seconds however, this is an arbitrary assumption and actual time depends on the length of time it takes to flush water out of the pipes back to where it is considered CLEAN. This leads to probably my biggest question (city water source) – where is the water considered CLEAN versus potentially UNCLEAN – is it the city main in the street where the feed to my home occurs?; is it the point of entry into my house? What makes one point CLEANER than another? If I’ve been gone for two weeks, there is a very long chain of water that has probably had little movement. In this case, I’d think the safest (bacteria-wise) would the 140-150 degree water in the water heater after I’ve allowed the water to come up to full temp and sit for a couple of hours??
6 – In considering only consuming bottled water, I see a different set of trade-offs. In this case you’ve got multiple container transfers which involve sanitation of every container and transfer mechanism along with several exposures to air all of which would seem to be potential sources of contamination.
In conclusion, I’m going to continue my reckless consumption of water from the hot water tap. Our household consists of just my wife and I. We have several bedrooms and baths that are not used for extended periods – I do routinely run water into the traps so they don’t dry out. After searching info – I will flush the faucets and showers, both hot and cold, prior to company – CDC recommendation if not used recently (a week).
My comments are in the context of someone that grew up frequently drinking water from a garden hose (lived in CA and it got hot playing outdoors). I have never lived in an ‘older’ home and generally never considered lead paint or solder as having been used in construction.
I have upgraded the water supplies of most of the homes that I’ve occupied as an adult – larger capacity, faster recovery water heater, filtration systems, water softening, recirculation, mixing valves, etc. I all of this I’ve never seen a warning about consuming heated water – this seems odd given the often ridiculous warning labels found these days.
I find myself somewhat skeptical of the information I’ve found – at least in my context of concern.
1 – hot water leaches lead out of pipes and fittings more than cold water – I can see this as a concern if unsure of construction. This doesn’t apply to me.
2 – hot water may be more prone to contamination because there are more components – I have trouble buying into this as once a system is constructed and flushed it is then sealed. This concern would seem to apply to longer pipe runs with more fittings as equally other sealed paths. This would seem to also apply to refrigerators with water and ice makers.
3 – For the last 20 years I have kept the water heater at 140-150 degrees. If I read sources correctly, water stored at this temperature should be safer from bacteria than unheated water (it also extends the availability of bath/shower water). I use mixing valves so the water is delivered to faucets/baths/showers at 115-120 degrees.
4 – I’m going to discount the potential leaching of compounds from PEX lines as I generally do from plastic water bottles and such – I just don’t see the normal volume of usage and/or the delta of such leaching between hot/cold water as reaching a level of concern. Most of the water I consume is from my refrigerator (combination of ice and cooled water) – this would seem to have a concern similar to #2 in that it puts more components in the chain from source to consumption??
5 – The time and temperature of water sitting in pipes can contribute to bacteria growth – lukewarm water over longer periods of time is conducive to bacteria. This applies equally to hot water cooling off and cold water warming up as it sits in pipes. Some sources suggest that any water sitting in pipes for 4+ hours is suspect and should be flushed. Many flushing suggestions specify 30 seconds however, this is an arbitrary assumption and actual time depends on the length of time it takes to flush water out of the pipes back to where it is considered CLEAN. This leads to probably my biggest question (city water source) – where is the water considered CLEAN versus potentially UNCLEAN – is it the city main in the street where the feed to my home occurs?; is it the point of entry into my house? What makes one point CLEANER than another? If I’ve been gone for two weeks, there is a very long chain of water that has probably had little movement. In this case, I’d think the safest (bacteria-wise) would the 140-150 degree water in the water heater after I’ve allowed the water to come up to full temp and sit for a couple of hours??
6 – In considering only consuming bottled water, I see a different set of trade-offs. In this case you’ve got multiple container transfers which involve sanitation of every container and transfer mechanism along with several exposures to air all of which would seem to be potential sources of contamination.
In conclusion, I’m going to continue my reckless consumption of water from the hot water tap. Our household consists of just my wife and I. We have several bedrooms and baths that are not used for extended periods – I do routinely run water into the traps so they don’t dry out. After searching info – I will flush the faucets and showers, both hot and cold, prior to company – CDC recommendation if not used recently (a week).
It’s a long read but IMO it’s a good read.
I concur with this opinion.
https://www.phcppros.com/articles/3000-domestic-hot-water-re-circulation-systems
If you don’t want to read the entire article, you can scroll and start here in the linked article.
“ Demand circulation controls dilemma “
It’s speaks about cold water return systems.
I concur with this opinion.
https://www.phcppros.com/articles/3000-domestic-hot-water-re-circulation-systems
If you don’t want to read the entire article, you can scroll and start here in the linked article.
“ Demand circulation controls dilemma “
It’s speaks about cold water return systems.
Here is another article by the EPA that warns about elevated lead content in some hot water systems.
https://www.epa.gov/sites/default/f...ance_lcmr_lead_public_education_poster_v1.pdf
https://www.epa.gov/sites/default/f...ance_lcmr_lead_public_education_poster_v1.pdf
Articles from above along with years of field experience tells me that I should drink the best water available to me and that is rarely if ever going to be water that’s been sitting in a water heater. 
