(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 4 of 4

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

  1. #1

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

    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.

    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...

    Any thoughts much appreciated!

  2. #2
    Master Plumber master plumber mark's Avatar
    Join Date
    Feb 2005
    indianapolis indiana - land of the free, home of the brave....
    Blog Entries

    Talking 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 by master plumber mark; 03-17-2007 at 12:12 PM.

  3. #3
    In the Trades kordts's Avatar
    Join Date
    Oct 2005
    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. #4


    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.


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts