shut off tank when on vacation

Discussion in 'Water Heater Forum, Tanks' started by netmouse, Oct 14, 2013.

  1. JerryR

    JerryR Member

    Messages:
    237
    Location:
    Florida
    I'm with Dana on this.

    My water heaters are kept at 140dF with tempering valve supplying the house with 110dF hot water.

    I currently have 3 houses that we travel between. When we leave any house for anything more than overnight we go through our 5 item shutdown checklist.

    Turn the ice maker off in the refrigerator
    Turn off the house main water ball valve
    Turn off the water heater breaker
    Set the air conditioning to."away" mode
    Set the Burglar Alarm.

    I can monitor and adjust air conditioning remotely via Filtrete Radio Thremostat
    I can remotely control Alarm via Invisalink
    I can remotely monitor all entrances and interior via ip cameras

    Before arriving after being gone for period of time I remotely adjust A/C a few hours before arrival

    After arriving
    1- turn on house main ball valve
    2- enter house and run Hot water for a minute to expel air if any
    3- turn on hot water heater breaker
    4- turn Ice Maker on

    This has been working fine for years.
  2. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    You couldn't be more wrong. I was a Navy Hospitalcorpsman during Desert Shield/Storm. My local interest in the VA just reinforced what can happen and how easily lives can be changed and ended by what others consider an "extremist" view. It's a shame that my fellow veterans who served during war and peace died and were sickened when it could have been prevented. I just like to give the public the best care that I can as a plumber as I did to Marines and sailors during my service.
    Additionally, if somebody acts like a stupid-dummy-clown by contradicting advice that is sound and sensible from a seasoned professional, just so they can feel smarter than the guy giving the advice...then sure, stupid is as stupid does. What, can't anybody agree that my advice was sound? Does it have to be contradicted and give the OP a sense of safety because the stupid plumber is being EXTREME? C'mon. Just because I didn't lay down like a chump when the gang got all mobbish doesn't mean I was any more wrong, but the group would like to may it seem so.
    10 years ago when the type A influenza epidemic swept the country my 2 year old daughter and my wife, 7 months pregnant, spent 2 weeks in the hospital and almost died as a result of the virus. Am I afraid of the world now? No. I simply have my kids wash their hands after school, before meals, etc. It is a FACT that risks are reduced by hand washing. It is also a FACT that by maintaining proper temperature in a hot water tank is the best way to reduce the risk of legionnaires disease. That was all I was explaining before the smart-ass comments started. I have given thousands of DIYers and trade pros advice on forums over the years and have never found such resistance towards good advice before coming here.
    Last edited: Oct 17, 2013
  3. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    I'm glad that it works for you, JR, but if somebody asks for advice on a forum I will always give the safest advice. There is no reason for anybody to undermine the smart action to a problem just because it is different than their own as seen above. How many people in this thread have had to go into a persons house and actually be responsible for the safety of the water system and be held accountable for the outcome if something goes wrong? It's easy to give a careless answer when somebody else has to suffer the consequences.
  4. Dana

    Dana In the trades

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    2,805
    Location:
    01609
    I don't know much about "smart", but I s'pose us ignorami should just take the word of some un-credentialed anonymous web-poster (on the internet no less) who seems to prefer silly insults to citing reference when others disagree. Thanks for setting us straight on that.

    If you need the raw data of actual biologists and the investigative findings of public health researcher chasing actual cases, there are troves of real science available on the web. I've reviewed this topic multiple times in multiple contexts, reviewed quite a few published scientific documents available on the NIH website and other credible over the past couple of decades. If you can point me to a credible source that can correct or update my recollections on the where the growth risk temperature zones are, or new information on how new colonies can get established and grow in tanks that are allowed to stagnate at room temp, I'm interested.

    The very reason 140F has been established as a mandated storage temp under plumbing codes (and tempering of hot water coming out of those tanks to protect against scalds) comes from decades of evidence that 140F storage temps does indeed kill legionella and that 120F water does not. Storing water at 120F won't kill legionella, or reduce the size of already established colonies, but that legionella colonies won't increase at that storage temp. (Need sources for that?)

    I recall reading about a case at a medical facility in the Netherlands in the late 1900s, or maybe shortly after Y2K where the legionella outbreak was traced to COLD water distribution plumbing, where a section of the cold water distribution plumbing ran along side the heating system plumbing between floors in a plumbing chase, and that section of pipe regularly stagnated to about 100F every weekend when no cold water was being drawn. The investigators determined that the repeatd stagnation in the high-growth temperature zone allowed legionella biofilms to get established in that section of plumbing. (The article is probably still available on line, but it's in Dutch- jammer he'?) That's a typical scenario of real world cases- chronic stagnation at an optimally bad temperature.

    I've looked for (but have yet to find) any cases in the literature where hot water storage tanks normally kept at 120F+ temps allowed to stagnate at room temp developed legionella colonies. Once these colonies get established it takes 140F or hotter temps to kill them, but generally speaking, the places they get going easily are where they stagnate in the 85-110F zone. Simply passing through that temperature for a few hours several times per year, with storage temps at 140F before & after the periods where the temperature slewed through the danger zone doesn't have much risk- you're killing off any legionella introduced to the tank during active heating periods, and letting it stagnate in the off periods to well below where the colonies can grow. Call that logic a juggling circus clown act if you like, but when you do, show me a documented case (even one) where that has actually happened. Of the dozens of actual documented cases I've looked at previously, none fit the profile.

    I'm neither a medical nor pubic health professional, but I probably dig up and read more medical, scientific, & technical source literature on topics I'm interested in than the average hack. (I'm not a fan of Wikipedia- often the referenced sources in the footnotes on Wikipedia are from credible sources, but often not.) I'm all for educating myself- rather than making bald assertions & inane insults, cite sources. Your word alone really isn't worth much, given that your level of discussion rarely strays from the "cute quips and sassy witticisms but actually contribute nothing" you accuse others of.
  5. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    Dana, I've met you before. You're the hypocrite who doesn't even read your own text and are too arrogant to entertain the idea that what you say about others also applies to you.
    "I don't know much about "smart", but I s'pose us ignorami should just take the word of some un-credentialed anonymous web-poster (on the internet no less) who seems to prefer silly insults to citing reference when others disagree. Thanks for setting us straight on that."
    You appear the same way to me and any others who visit this site. I have yet to see any specific sources listed from you or any indication that you aren't just copying snip-its of text from a website.
    Drop the mightier-than-thou act and reread my response to the OP and your follow up responses and see how YOU have taken this to an extremist's level and went on your own little tirade of trying to make sense of a problem that doesn't exist.
    Silly, silly Dana. You suckered yourself into becoming me by not paying attention and trying to play calm when your emotions were actually getting the better of you.
    This is getting boring...really, I gotta go to work now and find praise and validation from somebody who knows my job better than me...oops, that's not me, that's somebody else...my mistake. Hee, hee. ta-ta-for-now. See ya on the forums!
  6. netmouse

    netmouse New Member

    Messages:
    84
    Location:
    NJ
    Thank you! Very helpful.
  7. DonL

    DonL Out of the Trades

    Messages:
    3,921
    Location:
    Houston, TX
    So if I understand Caduceus correct, You need to drain your tank and all of your water pipes, Or you could wake up dead.
  8. guy48065

    guy48065 New Member

    Messages:
    111
    Location:
    SE and north MI
    If legionella is so well understood and controllable how come this Pittsburgh VA hospital has been killing patients since 2007?
  9. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    See what I mean...just more smart-ass comments. A simple safety measure that even a child could understand and Mr. MENSA just doesn't get it so he replies with babble. Nice. Real class act, Don.
  10. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    Hospitals, Institutions and homes have had legionella issues with water and air conditioning for years world wide and will continue because some people cut corners, give and get bad information, aren't trained and educated or don't care. On another forum a legionella hazard was discovered by an HVAC tech in a where a new furnace and AC unit was installed by an unregistered contractor. This was just a few weeks ago. Like I was trying to do on this thread, initially. Give good advice, not carefree advice.
  11. Dana

    Dana In the trades

    Messages:
    2,805
    Location:
    01609
    Sure, my emotions get the better of me all the time, but if Caduceus has actual information to share I'd like to see what it is. If that info isn't available on the internet fine, I have multiple medical professionals (one is a research MD/Phd) and multiple PHd biologists in my family, and can get second-hand access to published research that may not be readily via internet sources.

    Without outlining the mechanism by which letting the tank stagnate to room temp it's hard to assign much credibility to a point of view. Simply asserting "you don't know what you're talking about" isn't very illuminating.

    According to the CDC data the prevalence of legionella in the US is over 300,000 reported cases/year reported, which is more than 5x the risk of getting hit by lightning. It's a real public health problem, but the increased risk factors from potable water systems come from tepid-water stagnation, not room temp stagnation. If your normal storage temp is at a lethal level, I don't understand the mechanism by which letting it cool to room temp with no flow carries any significant elevation of risk. If water is stored at only 120F there is a theoretical elevation of risk by the few 10s of hours it spends in the high-growth temperature zone.

    All ad hominem BS aside, I'd really like to know how this works.
  12. DonL

    DonL Out of the Trades

    Messages:
    3,921
    Location:
    Houston, TX

    Really ?

    Just tell us what needs to be done. I have yet to see you post what should be done.

    Please get Your head out of your ass, so that I can read your mind, and share your expert opinion.


    Have a great Friday also.
    Last edited: Oct 18, 2013
  13. guy48065

    guy48065 New Member

    Messages:
    111
    Location:
    SE and north MI
    Same here. My curiosity is piqued. I think most of us agree with the unsubstantiated principals Cad is saying, but that this thread is a mis-application of those principles.
    Nobody is disputing legionella exists, it's bad, it kills when inhaled...but it's not active in my water heater at 140F or at ambient.
  14. DonL

    DonL Out of the Trades

    Messages:
    3,921
    Location:
    Houston, TX

    Medicine kills also. I would rather have the problem, than the side affect of medication.

    Doctors are always practicing. What do they know ?

    First thing they ask is "What is wrong with you"

    I pay them to know, not to kill me with their Fix All.


    People are living to long and going Nuts, and we need to Purge...


    If you go to your remote cabin, with your loved one and die from drinking bad water, Then more power to you both. It will not happen unless it is your time, You can not change that.


    Not much hope for the world as we know it. Nothing is safe now a days.


    That includes the GOV and what they say is good for You.
    Last edited: Oct 18, 2013
  15. Dana

    Dana In the trades

    Messages:
    2,805
    Location:
    01609
    I'm more curious to know what temp your tank is averaging when you're away and running on pilot-only. A small amount of legionella introduced before you turned it down and head off takes awhile to die off even at 140F. If the 90% of the time you say you're away the tank is running say, 105-110F there is at least theoretically some risk that a late-innoculation of legionalla might survive, then thrive, a risk much higher than if it were allowed to cool to room temp.

    In the absence of actual evidence that there is an increased risk when a tank normally run at 140F is allowed to stagnate at room temp for weeks/months providing a plausible narrative on how that risk might rise under those circumstances would be useful. The risk is never actually zero in almost ANY scenario (even storage at 140F) but in terms of the magnitude of risk, it varies a lot with the circumstances. The amount of legionella that could actually form over a few days as the temp decays through the active zone from a nearly-sterile 140F to an inactive room-temp would be quite limited- more than would happen were the tank maintained at 120F over the entire week/month/year of no-flow. But it doesn't seem plausible that it's anywhere near the risk of pointing the five-iron skyward on the backswing while taking a shot from in the middle of the par-4 fairway during an active lighting storm. If there were even a single case in the literature of detectable legionella from a potable storage that followed anything like the time-temp profile of letting a 140F tank drop to room temp and dwell there for a substantial length of time I might be convinced. But from the published information on how this stuff actually behaves in potable water systems, I'd be VERY surprised indeed.

    Big vats that are rarely purged and maintained at danger-zone temps like hot-tubs become pretty serious legionella reservoirs. Be sure to hold your breath in the hot tub, eh? Seriously- if you can't smell the chlorine you may not want to soak in the hotel spa. Even though the risk is still small, it's probably several orders of magnitude higher than the room-temp hot water heater scenario.
  16. DonL

    DonL Out of the Trades

    Messages:
    3,921
    Location:
    Houston, TX
    I do not think the pilot on a heater will do much good to keep water warm.

    It may keep water from freezing.

    The differential on a gas valve can be as much as 20 degrees.
    I think most electrical controls may be around 10 degrees.

    So even in normal use you could die.

    The new thermostats that I have seen will not let you crank the temp, or you may hurt yourself.


    Just shoot me now.


    P.S.

    Dana, I think your theory is good. It all depends on the water quality.

    NASA may pay you to pee then drink your own urine. Astronauts do it.

    How sick is that ???
    Last edited: Oct 18, 2013
  17. Dana

    Dana In the trades

    Messages:
    2,805
    Location:
    01609
    Actual measurements indicate the contrary, especially in temperate or warmer climates. See the graph logging flue temps and hot/cold water temps in the middle of Tom Murphy's blog discussion:

    http://physics.ucsd.edu/do-the-math/2012/03/pilot-lights-are-evil/

    OK so this guy isn't a rocket scientist, he's an astrophysicist, but his hands-on lab measurements are no worse than the average HVAC pro. ;-)
  18. DonL

    DonL Out of the Trades

    Messages:
    3,921
    Location:
    Houston, TX

    lol

    That was good.

    To think that all of those BTUs went to heat the water in the tank is a bit funny.


    Being a Rocket Scientist , we do not play with anything hot under 1500 deg F. And the Cold stuff is way below 0.
  19. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    Your head must be up your ass if you didn't read the 6th post in this thread.
    "I could never recommend allowing a water heater to drop below the 120 deg.F. mark for any period of time. If you are gone for just a few days, what is the harm in leaving the tank stay as it is. It is unknown at any time how much legionella bacteria may exist in your public water system at any time. Typically there are low amounts of microrganisms depending on what type of chemicals are being used for water treatment and they have no affect on us because of the low concentration. But don't try to sell yourself into an idea that promotes a lack of safety, err on the side of caution.
    Some may say that they have never gotten sick from their hot water, but may have and not realized it. The symptoms are the same as the flu and may take just as long after exposure to show the symptoms. Children and the elderly are especially susceptible to the health risks when exposed. Rarely is ingestion of contaminated water a cause, unless aspirated. It is when taking a shower that it is inhaled with the vapors and settles in the lungs.
    The ideas that water sits in the pipes anyways and that temperatures drop in the tank when cold water is used are geared towards ignoring the core issue of safety with your water system.
    Just flush the pipes when you walk in the door and keep your tank at the normal operating temperature and you won't have to worry about Pasteurizing your tank or chlorinating the piping. "

    Or if you're having trouble with all of the letters and words...."Leave the tank on, it couldn't hurt". That was my reply before the barrage of smart-ass comments. To think you've been shooting your mouth off this whole time and didn't see my first post. You've really shown your arrogance many times in this thread...it's actually quite impressive. Now you can save your money from those ESP classes and spend it on charm school.
    Last edited: Oct 19, 2013
  20. ImOld

    ImOld New Member

    Messages:
    73
    Location:
    In the rumble seat
    I'm, at this very moment, having my septic tank pumped out.

    Too bad I can't get this thread sucked out also.

    Little did I realize, at the beginning when using the descriptive "inane", that this thread would evolve and descend into something suitable for a cesspool.

    Very appropriate for a plumbing forum.

    Carry on.
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