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I could not find thread on legionella...

I had my service tech in this morning to do several things, one of which was to install a thermostatic mixer valve at the output of the hot water heater before it enters the slab of the house and goes to all the hot water loads. There seem to be two basic types. One, that I thought to use, meets ASSE 1070 specifications, such as a Caleffi 5213 series. The other type meets ASSE 1017 specifications, such as a Taco 5120 series.

I get the idea that usually you use a 1017 at the output of a hot water heater, and a 1070 near the point of use. My guess is that a 1017 is cheaper than a 1070, from looking at their diagrams on how they work. The Caleffi 1070 valve is a lot like the Lawlor valve in my darkroom, and seems to be the best to use for me. But I do not know plumbing codes. Is there any reason why I must use a 1017 instead of a 1070?

The technician was reluctant to put one in, though he said if I insisted, he would do so. He says he spends a lot of time removing thermostatic mixer valves because they are unreliable, and more trouble than they are worth. He said legionella is only a problem for people in hospitals and young children. My immune system is still OK, but I do not know how it will be 10 years from now. He said the water is chlorinated and asked where the legionella would come from. I am not sure if it is enough chlorine to kill an infestation once it gets going.

Anyhow, I decided not to argue with him today, but wonder what others' experience with these kinds of valves are.  Could he be referring to valves made by inferior manufacturers?  I would assume that Caleffi and Taco have good reputations. If I had to pull a valve out every 5 years to clean the filters, I suppose I could deal with that. But if I needed to replace one every year, I would not like that.


  • NH03865
    NH03865 Member Posts: 38

    You can search the wall, there are lots of articles on Legionella.

    Here is a link to one of the threads


    Mark Eatherton has a link to contractormag.com.  I would suggest you follow it and read the articles.  Very informative.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    I am convinced.

    I am convinced that as I get older, I will probably become more and more susceptable to legionella from my shower head. My contractor is opposed to this becaue he says the tempering valves are all unreliable and the customers have him remove them. He will if I insist, install one. My main question is what one?

    The tempering will have to be done very close to the output of the hot water heater because all the hot water piping is embedded in the concrete slab. It seems a 1017 mixing valve is suggested (required?) at the heater location. But manufacturers seem to say that a 1070 valve should be installed in addition near the point fo use. Now I could do that for my kitchen sink and my bathroom wash basin. But not the shower, where I would have to rip out cabinets in the kitchen to get access, and retile the bathroom walls afterwards. That gets to be too much money. It seems to me that installing a 1070 valve at the output of the hot water heater would do the job, but the data sheets seem to say there is a risk of scalding if I do that. I have been unable to see why that would be true. If I read the data sheets correctly, they mostly require a 1017 ahead of a 1070 valve.

    I can tell my contractor to install one of these valves, even if he does not want to. Or I can hire another plumber to do it. But if I end up being the design engineer on this job, I need to know just how to go about it.

    So question 1 is if I set the hot water to 145F, and use a valve there, should it be a 1017 or a 1070? And whichever I pick, if I set the valve to abou125F 9120F in the case of a 1070 valve), do I really need a 1070 valve at the point of use too?

    Question 2: There seem to be four major manufacturere: Caleffi, Honeywell, Taco, and Watts, and others also. (I have a Lawler pressure-balancing thermostatically controlled 2-stage valve in my darkroom). How do I ppick a brand and type of valve?
  • meplumber
    meplumber Member Posts: 678
    The development of your knowledge has been great.

    JDB you have become a trusted voice of the homeowner on this board.  Congrats.

    I along with many of our fellow wallies, prefer the Honeywell AM series mmixing valves.  They are very reliable and easy to replace should a problem arise.  I install valves on all 3 sides of the mixing valve.  They are set and forget valves.  On all of my systems, I design for a 140 deg F + tank and set the honeywell at 120.  No complaints.

    Good Luck.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,333
    What Meplumber said

    I second his post.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    My thought is to install a Honeywell AM-1 series

    and then run the hot water heater at 145F. Set the valve to 120F or slightly over (125F) so it cools down to 120F or so by the time it gets to the shower.

    My next questions are:

    1.) Should I get a C series or a STD series valve. I would have thought to get the C series that goes from 70F to 120F. Data says the minimum required temperature dirrerence between hot and mix is 3F, which is great. My Lawlor photo valve requires 15F, but it is user adjustable from about 60F to 120F and has a pressure balancer as well as a temperature regulator in it. I would have thought that would be the one to get.

    But the Installation Instructions say "Mixed water temperature is dependent upon the inlet water temperatures at both the hot and cold water ports. The maximum of 120F can only be reached when the hot water port inlet temperature approaches 180F. If mixed water of 120F is desired and the hot water port inlet temperature is less than 180F, select a "Standard" temperature range AM-1 Series valve which has a maximum mixed temperature of 145F. This seems tocontradict the previous paragraph, saying the difference must be 60 degrees, not 3 degrees. That is quite a discrepency.

    2.) Should I have a well with a thermometer installed after the mixing valve, or is their Thermostrip to set it once a sufficient thing? I am inclined to add a thermoemter, unless this is stupid.

    "The development of your knowledge has been great.

    JDB you have become a trusted voice of the homeowner on this board.  Congrats."

    Thank you. A lot of that knowledge development I got right here.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    edited April 2011
    Go with the standard AM series...

    And have him include unions (if not included) for all ports, along with isolation valves for future service, and definitely a bi-metal thermometer so you can set it correctly.

    As for valve failures, I've had maybe 1 of the Honeywell/Sparco valves fail on me. Took all of 10 minutes to rebuild. If hard water is an issue, consider installing a magnetic/electronic water conditioner on your homes incoming water main (treat EVERYTHING!). Your lawn will thank you as well :-)

    If your plumber still resists you, tell him that the "GOLDen Rule" applies here. You have the GOLD, you make the rules. If he wants your gold, he will have to play by your rules. Otherwise, find another player...

    If he is so seriously isolated that he can't see the forest for the trees, it might be time to let him go any way.


    There was an error rendering this rich post.

  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    edited April 2011
    rebuilding those valves

    The lawler pressure-temperature 2-stage valve in my darkroom I had to rebuild once. After 20 years of service. That is satisfactory. I installed that one myself, and rebuilt it myself. I assume I would have no difficulty with an AM-1 because it is basically simpler, as long as a rebuild kit will be available then. If it lasts 20 years, I will be 92 or dead, so it may not matter.

    If I tell the tech's boss I want such a valve installed, the tech will do it. His boss is the grandson of the founder of the firm.

    The model valve has check valves in it.  There is already a shutoff valve coming out of the hot water heater, so I will need only two more. 3/4 inch ball valves are not a major expense. I could do the whole job myself, but I prefer not to. I have soldered over 100 joints in copper tubing with no leaks, but that was all 1/2 inch stuff. I am pretty sure my old Bernz-O-matic torch is not enough for 3/4 inch tubing.
  • rlaggren
    rlaggren Member Posts: 160
    I sympathize

    with your not wanting to...   And it's a good accessible project to see how the contractor does. But 3/4" isn't much different from 1/2"

    MAPP gas will run OK through a regular torch and heat a bit more - costs 3 times more, but the whole job won't come close to using one bottle. I use a standard hardware store torch with MAPP gas to sweat 2" copper all the time.

    Your actual problems will most likely relate to stopping _all_ the water dripping from the lines and maybe some trouble with old dinged-up copper, depending on your installation. If there's no point to drain the system from at least 24" below your lowest solder work, you may need to find a way to blow water out of it or find a screw joint low down somewhere to loosen... With dry pipes soldering 3/4" is just a little slower than 1/2"; same moves, same techniques. Cut, ream (something most guys don't do), clean, butter, sweat.

    If you want to treat yourself, get one of those click-start torches. Most of them seem to fail after about 40-60 hours use, but IMHO they are more than worth the money even if you only sweat pipe once or twice a year.

    disclaimer - I'm a plumber, not a heating pro.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    Not wanting to.

    "But 3/4" isn't much different from 1/2""

    My former contractor had two guys doing the piping. A real plumber and an assistant. They ran one inch threaded pipe from the boiler up to the LWCO on the return side, the pressure relief valve on the supply side. One inch was the size of the pipes coming out of the boiler. They then immediately went up to 1 1/4 inch and went to the flow check on to two 1 1/4 x 1 1/4 x 1 Ts and switched to copper to get to my indirect. They then went to the boiler circulator and a flow check valve and switched to 1 1/4 inch copper for the rest of the near-boiler piping. Having done soldering for electronics (smalll electric soldering irons), I knew what a good solder joint looked like. I also plumbed my darkroom that involved 100 joints in 1/2 inch copper tubing. So when I saw the joints the assistent did, I mentioned to the real plumber that the assistant used too much solder and not enough heat. He said he knew and redid the joints. He said the assistant needed the practice. OK, but not on my job.

    These valves say the installer must be qualified and do it in accordance with the local codes. I do not know the local codes. I did read the New York City plumbing code from the late 1800s and have some idea of what is probably in those codes. Although I doubt the current codes tell how to run gas lines for the lights anymore, or how to make your own gas if you cannot get it from a utility. But I do know that I need anti-backflow valves in some places, vacuum breakers in others, etc. I find it strange that I am required to have an anti-backflow valve in the input change to my heating boiler, but not in the domestic side of my indirect hot water heater. If I put one in, I guess I would need an expansion tank and a vacuum breaker in there. I do not think I will bother at this point.

    "Your actual problems will most likely relate to stopping _all_ the water

    dripping from the lines and maybe some trouble with old dinged-up

    copper, "

    I have a ball valve at the output of the hot water heater, so I can shut that off. From there, it is downhill until it enters the slab near the level of my feet. At the house side, I can turn on the hot water and let it drain from the house. A vacuum breaker in my upstairs darkroom will open and let all that water out. I have no air compressor, so I am not sure how to get the last little bit of water out.  The pipe from the shutoff valve on the water heater to the slab is 60 year old copper, but it is only 1/2 inch. 3/4 inch comes out of the hot water heater and they reduce it to half inch. I propose to remove the reducer and run 3/4 down to the slab. So that will be new. The cold water is 3/4 inch, and the main shutoff to the house is right there. I see no good way to get the water out of there. My former contractor had replaced the piping there, so it can be done. 3/4 inch comes out of the garage floor and goes to the main ball valve. It then reduced to 1/2 inch, but my former contractor raised it to 3/4 inch to get to the (new) indirect hot water heater. So as far as this job is concerned, the cold water is all new (2 years ago) copper.

    I have never seen a plumber or contractor ream the pipes. I never heard of doing that until I found this site. I do not have a reamer, but I imagine a plumbing supply house would have one. In the old days that I can even remember, a good hardware store would have one, but there do not seem to be any good hardware stores anymore. My favorite was Wilkinsons on Washington St. in Boston. They were something like 4 stories high and had a machine shop in the basement where they would make you stuff if they did not have it. But that was over 50 years ago.
  • rlaggren
    rlaggren Member Posts: 160
    Yes, code is easier when you do it every day

    I was thinking only about the actual fitting connections.

    You don't need to totally clear your system of all water, just the pipe near your work. When I say "stop all the water dripping from the lines..." I mean the lines that you are actually working on. Sometimes when I need to sweat unto a vertical pipe that's got water sitting in it that won't go away I stick a piece of plastic tube into it and blow hard to eject enough water; sometimes I roll up a long bit of rag and screw it into the pipe and pull it out and ring the water out of it - a couple times. Your house service shut off is supposed to have a hosebib immediately by it on the house side which can be used to drain the system. If that's not there, you should still be able to drain your system low enough simply by using any sink - since your work would take place above the HWH and the sink would lower the water level of your whole system well below that level. If you mess with the pipes near the slab it gets more interesting but see below.

    If I understand you correctly, you're planning on changing the HWH output from 1/2 to 3/4 down to near the slab where it goes below ground to be distributed. IMO that's a waste of time and a small risk: A waste because you still have the bulk of the 1/2c distributing hot water, a small risk because any work always entails a small risk of goobering up a pipe and if it happens 1/2" above the slab, it may not be easy or even possible to sweat on that bit of pipe sticking out of the slab. That would make for a bad day, so even though it's a very slight risk, there is no real benefit and I'd skip it. Keep the work away from the slab unless there is a real need.

    disclaimer - I'm a plumber, not a heating pro.
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