Tankless alternative for Master Bath? (Marathon for rest of house)

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by dixiedoodle, Mar 17, 2007.

  1. dixiedoodle

    dixiedoodle New Member

    Messages:
    6
    Hello all. Would appreciate your thoughts regarding the following. Project is new construction. Master shower is ~8x8' with multiple heads and body sprays, all together requiring ~12GPM. Practically speaking, average shower usage will require ~8GPM, as all fixtures rarely will be on simultaneously.

    Property is serviced by 9GPM well (with reserve tank), and primary hot water source for most fixtures will be 85g Marathon tank.

    I am considering plumbing the master shower (as well as the two master bath faucets and roman tub filler) stand-alone, with a dedicated exterior-mount tankless (LP) unit.

    I am concerned that an 8GPM shower will drain the Marathon quicker than I will be able to leave for work in the morning before screams from wife wake the neighborhood. :eek:

    I am distrustful of the tankless units (which may or may not be able to provide hot H2O rises year-round in central Virginia), but can not think of any better solution. Bosch 250SXO or similar Rinnai would be contenders... :confused:

    Any thoughts much appreciated!
  2. no problems

    If money is no object , go for it

    but I think something that will handle your flow

    rate might set you back quite a lot of money.....


    It would probably wiser and cheaper to install 2 -50
    gallon gas heaters in series.....or a 50 and 75 would still be cheaper...
    Last edited: Mar 17, 2007
  3. kordts

    kordts In the Trades

    Messages:
    551
    Location:
    exurban Chicago
    Go with a Noritz 13.2 and you won't have any trouble. The Bosch isn't really a top of the line unit, and it's price reflects it. However if your pump is only capable of 9gpm, don't you think you need to upgrade, and get a bigger pressure tank?
  4. dixiedoodle

    dixiedoodle New Member

    Messages:
    6
    Thanks for the advice... I wish that I could use two tanks in series - but even 170 gallons (two 85g Marathons in series) would only provide ~30 minutes of continuous shower time - more than enough for me, but not enough for back to back morning showers... So, I definitely am going the route of a tankless, but as the above poster pointed out, only a handful of units are capable of producing 6gpm (the amount I figure I need, taking into consideration mixing hot and cold) with 50+ degree rises (central Virginia). Pricey project! I would not have gone down this path in hindsight. In any extent, thanks.
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