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Question on new Lochinvar KHB155--hot water

jcarsen
jcarsen Member Posts: 2
in THE MAIN WALL

Hello-

We have a new boiler that I believe was installed correctly. The factory defaults are:

SH1—125

SH2—125

SH3—125

DHW—120

The techs set our our boiler as follows:

SH1—180

SH2—125

SH3—125

DHW—120

We want the water just a little hotter than it currently is, for baths and such. Can I bump up the DHW, or will that mess anything else up? We have a separate hot water tank with no temperature dial or anything like that, so I'm assuming I need to adjust the boiler itself.

Thanks in advance for any thoughts!

Comments

  • LRCCBJ
    LRCCBJ Member Posts: 824

    You can change the DHW to anything you wish. Try 135° and see how you like it.

    Why is SH1 all the way up to 180°? Seems like he installer doesn't know what he's doing.

    jcarsen
  • hot_rod
    hot_rod Member Posts: 24,332

    DHW from an indirect tank?

    Plumbing codes list temperature supplied to various fixtures, tub and shower valves. They have never regulated the temperature of the water in the DHW source.

    There is also concerns about legionella at low temperature storage of DHW, 120 or lower.

    The trend seems to be maintaining the tank at 140f, use a mixing valve to regulate temperature to the fixtures.

    At the tank you want an ASSE 1017 point of distribution mix valve, if you run it at 140.

    At the fixture a ASSE 1070, this valve cannot be set above 120f, a point of use mix valve. Shower valves usually have pressure or temperature balance, some both, to protect the user.

    If you don’t have shower valves with scald protection, perhaps the plumber is reluctant to set the temperature higher?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    jcarsenGGross
  • jcarsen
    jcarsen Member Posts: 2

    Thanks so much to the commenters—I really appreciate your knowledge and insights!

  • Derheatmeister
    Derheatmeister Member Posts: 1,606
    https://forum.heatinghelp.com/discussion/comment/1838071#Comment_1838071

    180F may be needed if this is a Baseboard install !

    We like to start lower than most other contractors..The object is to keep the boiler condensing as long as possible (Below 138F at this Altitude.) and yet provide an accepted comfort level.

    On Most correctly installed radiant system we set our SH1 to approx 125F ish at -30F…. and 85F at 60F … WWSD we set to 55F to 60ish ….Ramp delay and Mod factor also need to be Adjusted on a case by case on order to prevent short cycling.

    jcarsen

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