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Navien 150

Docfletcher
Docfletcher Member Posts: 481
edited February 2016 in Gas Heating
This spring/summer I plan on replacing my boiler. The Navien NHB 150 has a turndown of 15 to 1 so I believe it may fit the bill to handle my several micro zones with 12 ft baseboard radiator sections. I've seen the video with Navien reps talking about this product at a trade show and when they said it would handle micro zones it peaked my interest. Of course I would need to go to a stand alone hot water heater but I don't see it as a problem. So I'm asking you pros to chime in with your thoughts on my going this route . One thought which concerns me is would it ever even get into condensing mode. 1600 sq ft raised ranch home in Ct. Thanks for your help.

Comments

  • Docfletcher
    Docfletcher Member Posts: 481
    edited February 2016
    Ah then I can keep my current indirect (HTP). Thank you for telling me of the Lochinvar. The Navien peaked my interest because of the 7700 btuh. These new tech boilers are a mystery to me. I like the idea of the micro zones not causing short cycles. So I'm trying to explore my options.
  • Docfletcher
    Docfletcher Member Posts: 481
    The spec sheet on the link you sent says it uses 12 amps. Is that correct, I mean will it be expensive to run?
  • Docfletcher
    Docfletcher Member Posts: 481
    edited February 2016
    Thank you for the information. :)
  • Docfletcher
    Docfletcher Member Posts: 481
    edited February 2016
    The current boiler is piped primary/secondary. I see you say the Knight can be piped direct and I would like to know if there would be an advantage to doing so? Also can you please give me a rough estimate of what the Knight list price is?
  • Docfletcher
    Docfletcher Member Posts: 481
    I've called FIA and I'm waiting on the rep to call me so we can discuss the product. Do you know if they make the KHN-085 in a wall hung version? Thanks Don
  • Docfletcher
    Docfletcher Member Posts: 481
    My boiler is out in the garage, the town requires 14 or 16" off the floor placement. My current WM sits on a metal stand. Since the Knight sits 41" off the floor I'm not sure how it would pan out install wise and service wise. If I can get the rep to come out we could go over all that and more. There is a feature I think I like very much, the multi temp loop control. I wish it did more than 3 loops though.
  • Docfletcher
    Docfletcher Member Posts: 481
    Just got off phone with factory rep. I asked him specifically .about that. He said the outdoor reset is needed so that zones not on the the 3 zone loop would operate at optimum temp. That's the way I understood it so take it with grain of salt. :) He also said I should keep primary/secondary and that the smallest boiler would work OK even with the indirect. Up to a 40gal indirect. Coming to look next week. I'm excited at the prospect.
  • Leon82
    Leon82 Member Posts: 684
    There are 3 odr curves and set points for the three sh terminals.
    The hottest one gets priority
  • Leon82
    Leon82 Member Posts: 684
    I should say it uses the hottest temperature when multiple Zone call
  • Leon82
    Leon82 Member Posts: 684
    There is also a parameter for mixing valve timer but I have not looked into that further
  • Docfletcher
    Docfletcher Member Posts: 481
    Literature says the multi loop will do 3 zones at 3 different temps while other larger zones will will run as hot as system determines required. Again, it's my understanding so take it with a grain of salt. I think that's where the outdoor reset comes into play.
  • Leon82
    Leon82 Member Posts: 684
    I have a whn from May of 2015. They may have made a software update but as far as terminals on the low voltage board there are three zones. Each one has its own ODR and set point. and set.. the manual states that boilers under 400,000 BTU are required to have an odr
  • Docfletcher
    Docfletcher Member Posts: 481
    Yep, rep says ODR comes standard.
  • njtommy
    njtommy Member Posts: 1,105
    edited February 2016
    I own a navien combi in my own house it's a nice unit, but after installing 2 lochinvar boilers this week I can tell you I really like the controls package on them.You can really dial in your water temps and ramp delays to get the most efficiency out of your system.
  • Leon82
    Leon82 Member Posts: 684
    I think you will need a mixing valve setup to run different temps simultaneously. I am using 2 set points but not to run different types of emitters. There is an icon on the display which shows which setpoint temp is priority.

    The boiler only has one output as far as I know.
  • Docfletcher
    Docfletcher Member Posts: 481
    they do mention control of up to 3 24v mixing valves.

    http://www.lochinvar.com/products/Default.aspx?type=ProductLine&lineID=186#
  • Leon82
    Leon82 Member Posts: 684
    Yes just making sure you knew it would be an option item.
  • Docfletcher
    Docfletcher Member Posts: 481
    Hatterasguy, I will do the 085 if the installers the rep is calling don't cause the deal to die do to high cost. The rep on the phone said the price I had in mind was doable. So I now am waiting to see.
  • Ironman
    Ironman Member Posts: 6,576
    The WHN wall hung only has a 5 to 1 turndown. The new KHN floor model has a fire tube HX and is 10 to 1.

    The multi loop control installs external to the boiler and will maintain up to 3 separate reset curves from the boiler on 3 separate floating mixing valves. The control is not cheap and neither are the mixing valves. It will constantly maintain the separate reset curves even if a higher temp loop is calling.

    I must ask: 12' of BB on a zone? I'd combine some of those zones.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    SWEI
  • Paul48
    Paul48 Member Posts: 4,470
    I agree......There are better options, than having a zone that small.
  • Docfletcher
    Docfletcher Member Posts: 481
    I plan on combining the two 12' zones upstairs. The downstairs bath will be tied into the family room zone yielding 28' of baseboard. The upstairs bath however is a vexing problem with it's 6' of Runtal 2 tier when it goes in. The only bright note there is it will rarely be used.
  • njtommy
    njtommy Member Posts: 1,105
    You could consider a buffer tank and keep your micro zones. It's an added cost, but at least you don't have to give up flexibility. It would also allow you to add other small zone in the future like radiant floor in the bath rooms.
  • Docfletcher
    Docfletcher Member Posts: 481
    Njtommy, Thank you. Do you mean a buffer tank with the Knight boiler? My plan "B" is/was a Burnham ESC3 with an Erogomax or as Hatterasguy suggested a Turbomax. I don't think I could afford the Knight with the added cost of the buffer tank :(
  • njtommy
    njtommy Member Posts: 1,105
    edited February 2016
    I believe the turbomax and erogomax can be used as a buffer tank? I could be wrong tho.
    If so the knight and erogomax/ turbomax would be a good combination.
  • Docfletcher
    Docfletcher Member Posts: 481
    Reverse pipe either one :)
  • njtommy
    njtommy Member Posts: 1,105
    It's pretty much free hot water in the winter months.
  • CMadatMe
    CMadatMe Member Posts: 3,085
    edited February 2016
    If you use a Ergomax/Turbomax aren't you just creating a new heat source instead of parking btu/hr being made by the boiler? Caleffi makes a nice buffer tank.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • njtommy
    njtommy Member Posts: 1,105
    I think the biggest thing is @Chris your not buying a buffer tank and a indirect tank. So your saving money on the cost of installation.
  • Docfletcher
    Docfletcher Member Posts: 481
    The thing that attracted me at first to the Ergomax is they say "The only unit that can heat domestic water, buffer boilers,. heat your house (baseboard, radiators & radiant). and do it all at the same time. " Current flyer says they have improved it with 2 extra connections to boiler. And I like it's low cost. However I have been told turbomax is better but it's almost 2ice the cost.