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Nhb 110 settings

bobby32x Member Posts: 23
edited January 2020 in Thermostats and Controls
Ok, I will try to disclose any and all info that I can think of while posting this for best possible accuracy. I live in upstate NY. My home is an old circa 1800's farm house that has been added on to by cob artists over the years. As I tear out rooms, I rewire, insulate and sheetrock each room as I go. This said, there are still walls in my home that have either settled blown-in insulation, or none at all.
My boiler (I installed with no prior experience, hence why I am here) is a Navien NHB 110. I have a FMZ-20 circ pump controller hooked in with a navien communication cable. I installed the Navien GFFM-MSOZUS-001 primary/secondary manifold system. I have a caleffi dirt-mag filter installed on the return. The zones and boiler pump are controlled by 3 Wilo star s 21f circ pumps. The upstairs zone is in 3/4" copper and the downstairs is in 1" copper. There are check valves installed after each zone pumps to prevent back flow when 1 zone is calling and the other isn't. To give you insight into how I have everything setup, I will list my dip switches in order to help diagnose what I have going on here.
On my PCB dip switches, I currently have 1 through 6 off. 1 and 2 off sets the boiler to "normal operations" I did this because the other settings tend to overshoot and I am assuming when all is running correctly, this should work ok in normal operations.
On my dip switches #2 (8 switch unit) I have 1 and 8 turned on. 1 on is to run in "return temp mode", 8 on is for the exhaust temp control "off" I chose the #8 dip because I felt like when I initially ran it, it was giving me an error due to exhaust temp and since I have the proper venting material(CPVC), the instructions say I can disable that.
On the front panel dip switches 1-10 are off and then the last 2 are on 1 is for fahrenheit, 2 is for using LP gas.
On my FMZ-20, all the dip switches are set to off.

on the boilers digital menu options I have it set like this:
A.ORC yes on. (Outdoor reset control)
B. 1 (1 for finned tube baseboard)
C. 0. (Lowest outdoor temp)
D. 70. (Highest outdoor temp)
E. 0. (Boost interval time (min))
F 100. (Space heating max capacity%)
G. 50. (Pump freeze protect temp)
H. 3. (Anti-fast cycling time (min))
I. 40. (Pump overrun time (min))
J. 100. (DHW max hear capacity%)
K. ---
L. 4. (Burner-off temp (*F)
M. 5. (Burner-on temp (*F)
N. 180. (Supply absolute max set point)
O. 104. (Supply abs. minimum set point)
P. 149. (Return abs. Max temp)
Q. 86. (Return abs. Min set point)
R. 6. (Lowest water pressure limit)
S. 0. (Initial start-up number)
T. ---
U. on. (SmartZone-link connection)
V. 30. (DHW priority time)
W. off. (Use boiler pump) should be on??
X. off. (System pump use)
Y. on. (Use DWH pump)
Z. 4. Not sure what this is, but its there
1. 1. (Low burning time during initial run)
2. 3. (Burning acceleration time to ch max)
3. 15. (Space heating min heat capac%)
4. 15. (DHW min heat capacity%)
5. off. (Warm weather shut-down temp)
6. 5. (Warm weather shutdown diff.)
7. --- ( increase or decrease the 70% default staging ON capacity%)
8. --- (increase or decrease the 30% default staging OFF capacity (20-40% range)
9 0ff. (Navi-link connection is enabled) should be on?
+ no. (Do not reset parameters (no)

Ok, so that is a lot, but I spaced it out for clarity and neatness.

I did a measurement of all the zones where there were fin tubes and here is what I have. Downstairs I have roughly 1055" or roughly 88' with 13 windows (all double pane glass with storms) 1 sliding glass door ( fairly new) and 3 steel entry doors, all with windows in them. Upstairs, I have roughly 965" or roughly 81' of fin tubing baseboard and 11 windows. (all single pane old style to match the house). I have been building frames for these windows to put a sealing edge on, in order to cut down on drafts.
Lastly, my symptoms. I have already been told that this boiler is far too big for my needs and I don't know about you guys, but I just dont have the money to throw at a new boiler when I have one that has a turn down ratio. I think I might be able to fine tune this one into doing what I need it to do, I just need help with the settings. I went into the menu and set my outdoor reset control to 0*F (originally +14*F). What is happening with my heater ( I don't think it is short cycling) is it never ramps up into a hot temp heating mode. it just casually heats up super slow (almost like a just a pilot light). We do a setback at night to 63 degrees (so we can sleep without opening windows) and then it kicks up to 70 on the thermostat at around 11am. Today, my wife noted that in an hours time, the thermostat climbed 1 degree. That can't be correct. It will take until bedtime to get up to 70 if it ever reaches 70...
Any help fine tuning this will be greatly appreciated. Bob


  • hot_rod
    hot_rod Member Posts: 19,884
    81 feet total fin tube? If so that will give you about 490 BTU/ hr per foot or about 40,000 BTU, no need to have more boiler than that. Question is if that is enough heat emitter. Only a load calc could answer that question.

    Parameter F look like you can derate that boiler, often on other brands 10- 100% . If this is correct a 110 boiler should be able to derate to 10,000 btu/hr. I'll bet your load is higher than that?

    Use this to get some good numbers. A few YouTube tutorials out there if you need help.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • bobby32x
    bobby32x Member Posts: 23
    Derate? Sorry, I'm not too familiar with terms and terminology for heating. Is this the same as a turn-down rate? This boiler has a 11:1 turn-down ratio if that's what you mean. Thanks for the help but the way
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,063
    edited January 2020
    I can see a small issue with 81 feet of aluminum fin on a single baseboard loop. The 81 ft... is that actual fin? or does that include any cover without fin..(only 3/4" pipe) ?

    Based on a rule of thumb, (Close but not actual) you may experience reduced output at the end of the loop (the closer you get to the boiler return) when you are close to design temperature, (coldest day of the year) after say about 65 feet of element.
    This rule is based on the following:
    600 BTU per lineal ft of element and cover.
    entering water temperature 180°F
    returning water temperature 160°F

    I use this as a guide from B&G for sizing and troubleshooting

    Your baseboard may have different capacities, for example, SlantFin fineline15 is rated at 550 BTU / Ft at those temperatures (so you can have more feet) and temperature difference, while Haydon's most popular model is rated at 660 BTU/ft (so you might have problems at 60ft). So, if you have an issue when it is very cold. You may need to up your water temperatures. You may need to up the temperatures through the entire outdoor reset curve.

    As far as your question: "Derate? Sorry, I'm not too familiar with terms and terminology for heating."

    Your boiler has a 110,000 rating. You can make that boiler a smaller boiler (virtual) by changing parameter F: to something less than 100%. For example, setting the F: to 80% will make the maximum boiler rating 88,000 BTU. The turndown ratio will not go any lower than 10,000 at a minimum, so your boiler will operate between 88,000 and 10,000.
    Currently, your boiler will operate between 110,000 and 10,000 (approximately)
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • bobby32x
    bobby32x Member Posts: 23
    Ok, so bare with me on this. The 81 feet is fin tubing. There are more lengths of just tube with a baseboard cover on it. I can measure the entire layout if it makes it easier. The thing is, the old boiler was hooked up to this very setup. The only thing I changed was I added a new boiler with a primary/secondary loop as required by the specs of the boiler. I hate to sound stupid, but my simple mind wants to believe that you could just cut out old boiler, stab in new, tinker with the settings and have the same or better heating system.
    By the way, the old boiler was a peerless purefire pf-110 that died because the water pressure regulator failed and the system was run with air in it while I was at work and the heat exchanger fried.
  • bobby32x
    bobby32x Member Posts: 23
    Also, if I throw the boiler into 2 stage max, I can get the house to over shoot the thermostat by roughly 3 to 6 degrees and it will maintain that temp for some reason. Even with the thermostat not calling anymore.
    Can you explain to me what the numbers mean on the outdoor reset control? Default is 14
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,063
    edited January 2020
    follow up:

    If you have a tee somewhere in the middle of the 88 feet of aluminum fin, and that feeds back to the boiler room in say 1" copper, then your not going to have an issue, because 1" copper can handle up to 80,000 BTU of water flow that can split into 2 circuits of less than 40,000 BTU each.

    This illustrates a problem system:
    This person complains that there is insufficient heat on the room served by the last 40 ft of baseboard radiators, only on the very cold days

    This is a way to fix that problem system:

    Illustration are from B&G Zoning Made Easy text and workbook
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    Alan (California Radiant) Forbes
  • bobby32x
    bobby32x Member Posts: 23
    Oh boy. I will have to map out the entire house to figure that out. However, there is a section of 1" pipe that goes for just so long and then it turns into 3/4". On top of that, there is a manifold where 3 or 4 pipes split off and this may have been to accomplish the latter of the 2 illustrations. I will have to map it out when I get out of work to confirm
  • bobby32x
    bobby32x Member Posts: 23
    Last night before bed, I went down and reset the boiler to factory settings. I then turned on the Navi-link setting and adjusted the low outside temp setting (cant recall what I set it to at the moment. I will follow up when I get home from work) and my wife contacted me today st 2pm and said "the heat seems to be working correctly right now"
    Now I know that this isnt enough testing to rule this project done, but whatever I changed, I must be headed in the right direction. What I think I would like to see is, which setting is the one that I need to adjust that makes the temperature ramp up to the thermostat calls first thing in the morning? When it switches from night mode to morning mode, prior to any settings changes that I made, it would take all day to get from 63 degrees to 69 degrees with a set point that bumps from 63 at night to 70 during the day. It would hover at 69 and not budge. I even thought I could trick the boiler when it wasn't paying attention and set the thermostat to 72, but alas, the temp remained at 69.
    NOTE: the old peerless boiler would ramp up in the morning and have the house warm in a matter of minutes.
    I know I am guessing here because I dont really know the layout of the actual piping, which I intend to look at later, but with a header of tee's that splice into the section of 1" piping, I bet it loops around 1 half of the house, and the other piping mirrors that. The upstairs zone goes in and out of each room and again, without really seeing the piping, I believe it does one continuous loop and then comes down and stabs into the backside of the header of tee's.
    Not knowing the dynamics behind heating systems, I was downstairs scratching my head as I noticed that the boiler had roughly 15' of 1" pipe before reducing down to 3/4". I originally thought that all of the first level heating was 1" piping. Also, the type of fin tube. You had mentioned a few styles and I still am unsure of what I have honestly, but I have find that are tin?? Aluminum?? Thin gauge steel? Anyway, they are about 2"x2" give or take, and each fin is sort of c shaped, or u shaped, whichever tickles your fancy and each one is spaced enough that just the outer fin is touching. They have red plastic guides that help hold them in place and provide a little protection from the sharp edges while handling. This is also what rests on the brackets to hold the pipes at proper level to allow air transfer from the bottom to top radiation.
  • bobby32x
    bobby32x Member Posts: 23
    Ok, just as previously noted, I was right. The loops go out and cover their area and then loop back around to the header as previously mentioned. So I think the 2nd illustration was thought of when the person put this plumbing in originally for the old setup. Also, the low outdoor temp was set from factory 14 degrees, to 0 degrees by myself. Everything is holding correctly, the thermostat is at 70, the temp is 71 and the boiler is off, waiting for the call to heat. I still dont think it is 100% just yet. Also, even with the p/s manifold and the check valves downstream from each zone ch, the heat is leeching through the ch for upstairs. The heat hasn't had to be called to this zone since I installed the new boiler. I thought the check valve would prevent backward flow to that loop but it seems that it must be going through forward even with the ch to that zone off and not calling for heat
    EBEBRATT-Ed Member Posts: 13,797
    If I am not mistaken he said he had 88' of baseboard on the first floor and 81' upstairs for a total of 169' x 600 btus/foot =101,000 btus
  • hot_rod
    hot_rod Member Posts: 19,884
    two loops one 81' and one 88'? A bit longer than what is recommended, as shown above but workable. The Star 21 circs are a bit higher head circ, so that is probably helping with the excessive zone lengths. you mentioned 3 circs, two zone and a boiler loop? Pics would help.

    Does the manual explain all the settings, what they mean and how to adjust them to your system?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • bobby32x
    bobby32x Member Posts: 23
    2 zones, each with their own ch and the boiler loop has it's own ch to help decouple it. I will get some pics. The manual explains them and some make sense, some seem like they are close to english but explained by a 5 year old, or I am understanding them like a 5 year old hahaha