NCB-180

JAL

I had recently had a Navien NCB-180 w/ODR installed in my house, after the install, I was looking at the piping and was woundering if was correct, I am no plumming expert, but I have piped in a lot of systems over the past 20 yaers as a Millwright, It seems to me that the return is not piped correct ???, to me it looks as though it is fighting it self with supply and return, the system is working fine and is modulating and condensing at times, due the fact it has been in the signal digits to low teens for a while, I live in the Chicago land area. I have included a pic, that was takin during install...let me know what you think.

Abracadabra

Picture is kinda fuzzy where I want to zoom in, but it looks ok to me.. what part are you refering to when you say "it is fighting it self with supply and return"

Looks like it is piped primary/secondary with 2 zones?

JAL

the return and supply are on dif sides, if zone one and zone two are running at the same time it seems that one has to over come the other , and that if only one zone is running that the supply and return are so close that the return would just get sucked into the suppy, am I wrong?

Ironman

It's called primary/secondary piping which provides hydraulic separation between the loops. Obviously, it's correct because the system performs correctly.

The only minor issue that I see is at the right side pump: there should be 8 pipe diameters of straight pipe between the Ell and Tee. I wouldn't bother with it though since it's working okay.

You can go to the on site book store and get Dan's book on "Primary Secondary Piping'" to understand the principal.

JAL

Thank You, Since I had this install I have been reading this fourm, which is very helpful.

JAL

I have another thing that has me thinking whats wrong. I set up all the parameters for ODR, and when I scroll through the menu its shows all my settings, The unit also seems to be modulating, when the temp gets warmer outside which it really hasnt gone above 33*, but the one day it did the supply temp topped out at 155*, which seemed to me that it is working, when I look at the main display that switchs between supply temp. and water psi, I dont see the icon for ODR. also when I got to the end of setting parameters it says...
This menu may be used to initialize all the parameters set with the
boiler. To initialize all parameters.
1. Press the [+] or [-] buttons to change the display to [Yes].
2. Press the [Mode] button.
3. When [No] appears on the display again, press the [Mode]
button.
OK when I do this itn allways reverts back to the NO on the display. is this actually set at this point ?

Ironman

I don't even try to remember how to program all the boilers, thermostats, modulating furnaces and heat pumps anymore unless I work with it everyday. They're too many of them, each one is different and I'm too old!

You'll have to use the I&O manual or see if someone else more familiar with that boiler wants to chime in.

JAL

Yea I went by the I&O, I just didnt understand why it acts the way it does when you get to the initialize part, it seems to be doing what it should, it just I want the small details
Thank You

Tim McElwain

Get in touch with your installer or Navien and they can walk you through it. I do not have my Navien manual handy it is at my training center.

JAL

in the above statement I copied and pasted exactly from the manual that is what it says when you get to the end. When you've established all your parameters I was just wondering why it does what it does after you change the display to yes then press the MODE button and no appears again and then you're supposed to press the MODE button one more time all said and done it still flashes no at the end, seems strange to me you would think that yes would be continued to be displayed I was trying to avoid ,calling the contractor or calling navien I thought somebody on this forum might have done this before and seen what I seen. but I really appreciate your answer everybody on this forum is very informative. thank you

jonny88

ironman you made a great point which a lot of people dont practice about length of pipe before and after circs.

wogpa67

I'm not famaliar with the Navien products. But on some of the other boiler makers changes to settings can only be made and stored when there is no call to the control.

JAL

I just noticed something after this install now that all the piping is cleared away, I have a baseboard in my kitchen that is hooked up on a return line to the boiler no piping from supply just one line that is pipe to the return for in and one line that is piped back to the return for the out of the baseboard it seems to work but I don't think this is right.I think that it should be piped to the supply side of that zone then to the return of that zone. My wife says it gets hot and works and if it's not broke don't fix it, I say it would work better if it was piped right. Any thoughts.

Ironman

Are you saying it's piped in series?

I agree with your wife: if it's working right, leave it alone.

JAL

Both inlet and outlet to the baseboard are piped to the same return line on the zone, maybe because the lines are right next to the boiler if you pipe the inlet to the supply it it would be pushing hot water right back to the return the baseboards only like 8 feet long,right above the boiler but looking at it I wouldn't think any water would go through it, but it does get hot

bmwpowere36m3

Must be in series…

JAL

Yes Thank You

Ironman

Is it monoflo?

JAL

not really sure what that is it does have just a regular tee one of the pipes the one coming back to the return line looks like it's a Tee with a check cause it says flow with an arrow

JAL

Thanks for all your help I'm not a HVAC guy by any stretch I have worked a lot of high horse power boilers and steam generators with hot wells and condensate returns .

bmwpowere36m3

http://www.comfort-calc.net/monoflo_system.html

JAL

here are a couple pics of the tee's in question this piping has to be 50 plus years old if look at it you can see that they
manually bent the pipe to hit the T

Ironman

It's piped monoflo. Since its been that way for fifty years and obviously works, why would you want to change it.

There are articles on site that describe this type of system. It's also called a diverter Tee.

By the way, if that's a monoflo Tee on the one next to it that's capped, then it's wrong. You don't cap off a monoflo Tee: you either pipe it back to the other Tee or remove the monoflo Tee. Capping it causes restriction that increases the system head and reduces flow.

Read the article and you'll get an understanding of how the system works. And, it's perfectly acceptable to use a monoflo Tee to connect a rad at the end of a return line on a direct return system.

Here's a link to the article:

https://heatinghelp.com/systems-help-center/diverter-tee-q-and-a/

JAL

Thank you, the caped line is not part of it, that is a dead DHW line, for whatever reason, not sure where it used to go, THANKS AGAIN. The last few days on this forum has been very helpful.