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Phase III question

cable 21
cable 21 Member Posts: 15
I have a job in a house with a kohler tub that holds 82 gallons to overflow. The house now has twined 50gall 40,000 btu heaters and runs out hot water near 3 /4 full.The house is occupied by two retired people no kids and besides the tub is the only time they have hot water problems.
I was thinking of putting a phase 3 heater in and saw that on the web site it gives plenty of capacity even on a 60 gallon phase 3? Is it possible if piped in 1 1/4 or 1/1/2 w circulator it will fill 82 gallon tub and still be hot enough for minor demand of faucets ect around house.
house has plenty of boiler capacity and now has 14 zones hooked up to two boilers.
any suggestions on priority heat controls with zone valves and this circulator zone would be appreciated.

Comments

  • Steve Minnich_1
    Steve Minnich_1 Member Posts: 127
    How are the

    water heaters twinned? Are they in parallel or in series? I'm no "stink'n plumber" but I believe they should piped in parallel with exactly equal distances from the bull of the tees for both the cold and hot connections. This way, in theory, hot water is drawn equally from each water heater.

    I would also consider checking to make sure there is no sediment built up on the bottom of the tanks.

    I would think in the situation you described 2 50's would be sufficient.

    I have three teenage daughters who take never-ending showers, a washing machine that never stops, myself-taking at least two showers a day, and a very clean wife-thank you. And we get by just fine with two 50's.

    I'd do some more troubleshooting.

    JMHO

    Steve, Radiant Comfort Systems

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  • cable 21
    cable 21 Member Posts: 15


    They are piped in paralel and where new five years ago and say they have always had this problem.
    Thier friend have a phase III and thats what they want.
    I agree that two 50's should do but one 60 phase III may be alot better? or not?
  • Dave Palmer
    Dave Palmer Member Posts: 186
    had

    the same job.Guy had a 100 gallon jazzuci tub and twinned 40's.He ran one at a higher temp and when he was going to use it he would crank the other one up too. We replaced them with a 60 gallon phaseIII off of the boiler as its own zone w/ circulator. Biggest selling point was he didnt have to worry about changing w/h every 7-8 years.Works great and very happy customer.
  • cable 21
    cable 21 Member Posts: 15


    thanks makes me feel better about the 60 phase III
  • Al Letellier
    Al Letellier Member Posts: 781
    Phase III

    We have a 75 gallon Phase III heated by a 100,000 BTU boiler feeding 20 motel rooms. We run the tank at 150 degrees and used an anti-scald mixing valve to deliver 115 degree water. the only time they ran out of water was when they ran out of propane. These tanks make A LOT of hot water. Use a 60 gallon, run it at 140 and use a good mixing valve.

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  • kevin
    kevin Member Posts: 420
    i'd keep the...

    two P3. Pipe it with a mixing valve (Sparco) and crank up the temp. to 150F or so. How fast are they filling the tub? If you have a have a 100 gallon water heater you really have only 66 gallons of hot water before the cold dilutes it out.Sounds about what you are getting.
    What boiler are they hooked up to? How fast does it recover from the draw? kpc
  • hot_rod
    hot_rod Member Posts: 22,817
    Best to define the load

    then size the equipment and piping to that. Often times in residential applications a bit of storage will be all that is needed to handle large evening dump loads.

    Determine as accuratly as possible how much DHW they need, the delta T you are looking at, and size from there.

    Nothing wrong with suggesting some conservation, for the sake of looming water and energy shortage issues :)

    hot rod

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    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mike glass
    mike glass Member Posts: 53
    twinned w/heaters

    Try piping the cold incoming to a tee and nipple at the boiler drain ports on the w/heaters. This should be sufficient if piped parrallel reverse return.

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  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Series/Parallel

    While the theory is that paralleled water heaters will draw equally, in practice it's difficult to achieve or even verify.

    A local rental property owner (mostly students with LOTS of showers/etc.) told me years ago that once he started installing two heaters in series there were no longer any complaints about running out of hot water. The series arrangement allows a large volume of hot water over extended time (like filling a large tub with 1/2" valve?). The parallel arrangement (if you can actually manage to get even draw) will allow a large volume of hot water in a very short time (like a shower of exceptionally high volume flow).

    I've personally solved one large-tub problem by changing from parallel to series and believe others with similar problems have fixed them as well with this arrangement.

    To keep the energy cost from being absurd, run the first tank somewhat cooler than the second.
  • Herb
    Herb Member Posts: 31


    Convert the heaters from the parrallel arrangement to series. This gives a boost of 15 gallons of hot water to your dump load. It also allows the burners to be stage their run duty. We use this format on dairy barns etc. and it also allows one heater to carry most of the load [or lime]. Certainly worth a try before committing to the expense of a boiler solution. Good luck Herb
  • Jeff_9
    Jeff_9 Member Posts: 7
    dip tube

    Try removing the cold water inlet pipe and check the dip tube. It wouldn't be the first time a dip tube failed


    Jeff
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