Lochinvar nkc199

wildwillyjohn

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

Alan (California Radiant) Forbes

hot_rod

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

wildwillyjohn

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

wildwillyjohn

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

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.

wildwillyjohn

Yes 2 zones one external pump

hot_rod

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.

wildwillyjohn

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

Alan (California Radiant) Forbes

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

Alan (California Radiant) Forbes

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.

wildwillyjohn

Big monoflow tee system no short cycling

Works great,other than circulator wired direct. CO perfect

wildwillyjohn

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

GroundUp

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.

109A_5

"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.

wildwillyjohn

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

@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?

wildwillyjohn

20260916_133232.jpg

20260916_133255.jpg

GroundUp

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

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.

109A_5

Are there two external circulators and a Buffer tank ?

wildwillyjohn

20260920_193935.jpg

Attached purple wire to circulator. Problem sol-ved

Thanks everyone

That boiler mate was for the old utica boiler set up