Can Someone Explain Navien's "ComfortFlow" Technology?

Discussion in 'Tankless Water Heater Forum' started by Haselsmasher, Apr 23, 2014.

  1. Haselsmasher

    Haselsmasher New Member

    Messages:
    4
    Location:
    CO
    I just had installed (yesterday) a Navien NPE-240A. After 24 hours I'd say it's doing great - but I sure would hope it's doing great after only 24 hours. LOL

    Can someone explain how the internal tank and internal recirc actually works? (I don't have a recirc loop in the house - so it's not doing any external recirc.) The manual and product documentation only says it's purpose is to eliminate/reduce cold water sandwiching.

    Does it keep the buffer tank hot all the time? Or does it only do the internal recirc if the buffer tank is hot and water is called for? I think the benefit in this scenario is some of the buffer is used to pre-heat the cold incoming.

    It's the details of exactly what happens and under what scenarios is what I'm trying to understand.

    Thanks.

    Jim
  2. cicerored

    cicerored New Member

    Messages:
    27
    Location:
    Clay, New York, United States
    The buffer tank is hot at all times. But as far as tanks, it is very, very small. It is also super-insulated, so it is not being heated all the time. It is just enough water to provide the initial burst of hot water
  3. Justin B. Williams

    Justin B. Williams New Member

    Messages:
    6
    Location:
    Pennsylvania
    i just went thru the basic entry stuff at my job for these units the "buffer tank" does actually get heated, but not often because of how well its insulated that is what the pump inside of the unit is for and also for a hot water reserc loop in the house .. the comfort flow tech in these units.. how it works it that the unit will do everything in its capability to keep that outlet temp at its set temp. it has diffrent phases in the heat exchanger and it can controll its own water flow and gas flow to keep the set output temp (if the unit is heating in high rate, and the output starts to drop it will back the flow rate down to bring the temp back up) its a really cool unit well worth the money, we have alot of happy customers with one of these
  4. Will Rogers Plumbing

    Will Rogers Plumbing Plumbing Contractor

    Messages:
    57
    Location:
    Moore, Ok
    The internal recirc doesn't do a whole lot. Works quite well though with a return line.
  5. Haselsmasher

    Haselsmasher New Member

    Messages:
    4
    Location:
    CO
    It has been 3 months and the unit is still doing great. I have a possibly related question........

    This evening I happened to be standing by the exhaust vent (outside the house) and noticed warm air coming out. There was no hot water running in the house. I went and checked the unit and confirmed the water output at that moment was 0 GPM.

    Would it be doing this because it's heating the internal storage tank? I assume it's considered normal to occasionally blowing out warm air when it's not in use but I'd like to confirm. (I figure the chances of me worrying about a non-issue is greater than the chances of there being a problem with the unit. :))

    Thanks.

    Jim

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