Lochinvar nkc199

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wildwillyjohn
wildwillyjohn Posts: 21
in Gas Heating

Installer hooked up circulator direct with WAGO so it runs constantly. I dont see where circulator connects inside to boiler.thought about using taco relay controller externally. Heat and combi hot water works but not correct

Thanks

Comments

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,876
    Screenshot 2026-09-14 at 11.53.58 AM.png
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • hot_rod
    hot_rod Posts: 28,606

    the combis have an internal circ that is factory wired

    Is it piped primary secondary? A loop pump snd zone pumps may need to be wired

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • wildwillyjohn
    wildwillyjohn Posts: 21

    Schematic shows brown wire no brown in bundle to lower junction box. Purple but no brown.

  • wildwillyjohn
    wildwillyjohn Posts: 21

    The contractor who installed this four years ago venting was two edge, emmanuel says three edge had a natural gas orifice. Its propane. Gasoline was too small for the run from the regulator I had to put a max attrol regulator there to boost the pressure. Gas company came out to do a tune up on it. A 1000 parts per million co should be like 20. My neighbor's an hvac guy. He got it all dialed in for me now. But I just noticed that the circulators running all the time

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,876
    edited September 14

    You can use the purple (system pump) wire. Do you have only one pump on the heating circuit?

    If the pump is more than 2 amps, you must isolate with a relay.

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • wildwillyjohn
    wildwillyjohn Posts: 21

    Yes 2 zones one external pump

  • hot_rod
    hot_rod Posts: 28,606

    The way you wire it depends in how it is piped. How many pumps?

    In any case all the pumps should shutdown if there is no heat or DHW call.

    Screenshot 2026-09-14 at 2.01.34 PM.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • wildwillyjohn
    wildwillyjohn Posts: 21

    I guess i can call for heat and ck if purple energized. Schematic shows purple going to pump also

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,876

    You could just connect the pump and see if it turns on.

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    wildwillyjohn
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,876

    Interesting installation. One pump, 2 zones (must be zone valves) on a 199,000 BTU boiler.

    I hope that each of those zones is large, especially since there’s no primary/secondary piping. Otherwise, the boiler might just short-cycle itself to an early death.

    From what @wildwillyjohn has said about the exhaust and gas installation, it sounds as though the original install was not done properly to put it delicately.

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • wildwillyjohn
    wildwillyjohn Posts: 21

    Big monoflow tee system no short cycling

    Works great,other than circulator wired direct. CO perfect

    Alan (California Radiant) Forbes
  • wildwillyjohn
    wildwillyjohn Posts: 21

    Original utica was 100k btu but no water treatment only lasted 10 years

  • GroundUp
    GroundUp Posts: 2,572

    Show us how it's piped. Noble combi boilers don't have a brown wire because there is an internal boiler circulator that's wired from the factory. The purple wire in the J box is for the system pump, as the label on it very clearly shows. How do you have two zones without zone circs or zone valves? Just two large TRVs? The purple wire is energized on any call for heat- just disconnect the line voltage currently feeding the pump and run a new hot wire back to the purple wire and you'll have a properly controlled P/S system if it's piped appropriately. If the circs are in series, it either needs to be repiped or the external one can probably be removed altogether.

    Alan (California Radiant) Forbes
  • 109A_5
    109A_5 Posts: 4,687
    edited September 16

    "Heat and combi hot water works but not correct"

    So it is a Combi ?

    The Combi version does not have external Junction Box access to the Brown Wire, since I suspect the Boiler pump is internal to the unit (as @hot_rod stated). The 'System pump' wire (the Purple wire) may do what you want.

    image.png image.png image.png image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    Alan (California Radiant) Forbes
  • wildwillyjohn
    wildwillyjohn Posts: 21

    Thanks for all the great info. That's what i was thinking the internal pump IS the circulator. I will hook up the purple

    Thanks community!!

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,876

    @wildwillyjohn The internal pump is your boiler pump. The external pump is your system pump. The two should be connected by either closely spaced tees (shown below) or a low-loss header. Can you verify?

    Screenshot 2026-09-16 at 11.08.06 AM.png
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    wildwillyjohn
  • wildwillyjohn
    wildwillyjohn Posts: 21
    20260916_133232.jpg
    20260916_133255.jpg
  • GroundUp
    GroundUp Posts: 2,572

    That does not show the primary/secondary piping. We need to see further to the left and verify whether there is any hydraulic separation. Also there are two external pumps but one has the valve closed. What is that for?

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,876

    I don't see a second pump and from what I can tell, it looks piped directly. If so, the system pump and boiler pump are in series, doubling the head.

    I can't tell if that's a Grundfos 15-58 or 26-99.

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • 109A_5
    109A_5 Posts: 4,687

    Are there two external circulators and a Buffer tank ?

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • wildwillyjohn
    wildwillyjohn Posts: 21
    20260920_193935.jpg

    Attached purple wire to circulator. Problem sol-ved

    Thanks everyone

    That boiler mate was for the old utica boiler set up

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