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would you use a Rinnai?

Chris_31 Member Posts: 19
tankless for radiant??

1500 square foot remodel, Wirsbo QuickTrack, Rinnai tankless, with a 30 gallon buffer tank.

The Rinnai will be used for both domestic and radiant, haven't done any loads yet, so not sure it will work for pottable and radiant, perhaps 2 units??

anyone have suggestions, designs, or ideas??




  • Dave Stroman
    Dave Stroman Member Posts: 761

    The correct answer is, no.

    Dave Stroman, Denver
    Dave Stroman
  • Jim_64
    Jim_64 Member Posts: 253

    I don't know that I would. Connecticut is the land of steady habits. If you want to use that type of equipment for space heating, I know that Noritz is designed for either/or space heating DHW. We have installed all of them for DHW and have settled on Noritz formany reasons not the least of which is it is made by the same people who make camrys and celicas.
  • tim smith
    tim smith Member Posts: 2,360
    Rinnai for heat & HW

    The FFUC units are rated for heat and hot water. We did one just lately for a guest house due to room & cost. Not my preference but oh well. Used brazed plate heat x to separate. Used reset for heater side pump of heat ex to modulate floor temp. Worked fine. Again it is not a boiler and not my favorite choice but worked.
  • Chris_31
    Chris_31 Member Posts: 19

    for the responses.

    not my preference to use a Rinnai, but thats what the customer has their mind set on using!

    I may end up going with 2 units, one dedicated for the radiant, and one for the potable. my load is 128k btuh so I know the Rinnai will hadle the load, especially if I use the comercial unit.

    thanks again

  • JackFre
    JackFre Member Posts: 225

    They are an excellent water heater!
  • tim smith
    tim smith Member Posts: 2,360
    Re use for one or the other

    In our jurisdiction we can only use one for heat if it is used for both heat and hot water. Just a technicality but required as this is how it is rated. Tim
  • I would use a Rinnai...

    for its intended purpose, that being instantaneous tankless DHW heating. I know, they have their product dually "certified", which means it can be used for either or,but unless something has SUBSTANTIALLY changed on the fire side of things, it is intended for one use and one use only, that being a fixed flow with a large delta T across the HXer.

    Times, they are a changing, and my good friend Greg Gibbs tells me that they (Noritz) have adapted their technology to that of varible fire input with extremely low input capabilites, so maybe they deserve a second look.

    But to my knowledge, most of them are still dealing with a BANG BANG flow controlled gas train that is not conducive to low flow and low delta T. The result of that misapplication in a space heating situation is an appliance that short cycles itself to death due to never really being allowed to acheive full combustion capabilities. I have replaced WAY too many of these misapplied appliances. The consumer is attracted to it because it "looks" like a boiler and is CHEAP. Don't let external appearances mislead you. It's the technology inside the box that makes it work the way it should...

    As for applications using one water for space heat and DHW, you can forget about that too. Unless you WANT to make people sick and possibly have them die from their system. If you MUST use (mis use) one of these appliances you MUST use a heat exchanger to isolate the two fluids.

    Take it from a legionella survivor. I wouldn't wish that experience on ANYONE.

  • rob_46
    rob_46 Member Posts: 2

    in stead of listening 2 opinions y not get the facts.Call Rinnai
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928

    128,000 btu sounds incomprehensibly high for 1,500 sq.ft.

    That's 85 btu per square foot and would require a floor temp of over 110F in a 70F room!

    And no, I personally wouldn't consider using an instant water heater for both DHW and space heating. If you want both from the same appliance (without using storage) then why not go with a so-called "combi-boiler" that IS designed for such use? Of course you must verify that it can provide sufficient DHW.
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