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Outdoor reset installed , questions

GtaGta Posts: 36Member
Hi

I have just installed a out door reset to my lion 23 kw boiler . It is set to 120 f and tonite it has warmed out outside to -14 c .

I can confirm that the max water temp at the moment has been reduced down to 115 f ( according to my lil laser thermometer) . I do however have a few questions.

I have 3 zones with 3 separate bell and gossett nrf 25 3 speed pumps all set to low.

I’m running.4 ish gpm the system seems to run a lot , and the boiler will quickly fire all elements get up to temp them shut all off and repeat/repeat this over and over until the stat is satisfied.

I’m wondering if I have too little water flow with too little water speed?

The main zone is 1/2 inch pex with 11 300 ft runs . How do I calculate head loss and compare it to the capability of my pump?

The next zone is same 1/2 inch pex 5 runs /300 ft each

The third and final zone is 3 runs 300 ft long . Thx in advance for any help or direction you can provide, s

Comments

  • SuperTechSuperTech Posts: 938Member
    Are you sure this is a flow issue? Sounds more like a malfunction or something configured incorrectly.

    I think B&G has an app that can help you figure out flow requirements
  • GtaGta Posts: 36Member
    Thx I checked out that app but it’s does not help
  • SuperTechSuperTech Posts: 938Member
    Have you tried adjusting flow to see if it makes a difference? I'm struggling to figure out how the outdoor reset is affecting your flow? Flow is the same with or without ODR
  • GtaGta Posts: 36Member
    Sorry I should have made my self clear , I was just posting that as added info , my main questions are about how to calculate head loss and flow rates in the 1/2 inch pex and circ pump speeds . Sorry for the confusion 🙂
  • GordyGordy Posts: 9,264Member
    edited February 12
    IF the desired flow through each loop is .6 gpm. The head would be about 3.82' for a 300' loop.

    The question is the piping friction losses to and from the manifold.

    .6 gpm for 11 loops would require that manifold to receive 6.6 gpm. 11x.6 = 6.6.

    The NRf 25 on speed one with 6' of head would deliver 10 gpm. More or Less than that as we don't know the rest of the piping pressure drop. The boiler is about 76k which would need a flow of 7.6 gpm for a 20 delta..

    Try speed two see if that helps, but speed one is right there.

    My apologies as I had to edit was looking at the glycol chart.

  • GordyGordy Posts: 9,264Member
    I see 12 loops. What are the other two circs to?

    Never seen a 4 way cross used in hydronic piping before........ with three circulator pulling through it , that must be an interesting flow characteristic.
  • GtaGta Posts: 36Member
    Gordy , thx for the reply. This boiler of mine puts all 4 elements on regardless of the aqua stat setting .... it quickly gets up to temp then shuts down and repeats this process. Is this normal? It seems to me that this would not be a efficient way to operate? I tried lowering the aqua stat and it acts the same regardless of temp , it was at 120 now it’s lowered to 110 and acts the same . Thanks in advance for any suggestions, Sean
  • GordyGordy Posts: 9,264Member
    edited February 12
    CEB 23 model? Is the thermostat anticipator setting at .2?
  • GordyGordy Posts: 9,264Member
    Thermostat on the wall for the room.
  • GordyGordy Posts: 9,264Member
    If it's not that it's flow. You can change to higher pump speed see if it helps. The trouble shooting chart gives those to issues for rapid cycling. The elements are not staged on that boiler.
  • GtaGta Posts: 36Member
    Yes I think so it’s run by a rehau dual sensing digital t stat
  • GtaGta Posts: 36Member
    It does not have a “ anticipator” setting that I can see in the menu..... am I missing something?
  • GordyGordy Posts: 9,264Member
    Try changing pump speed.
  • GordyGordy Posts: 9,264Member
    I'm assuming the thermostat was properly set up. Do,you have the manual?
  • GtaGta Posts: 36Member
    It does stage the elements... well it did before I swapped boards to install the out door reset. , I just sped up the pump to mid and it still acts the same , I am curious tho about the .2 anticipator setting , I’m going to attach a pic of the t stat menu.....
  • GtaGta Posts: 36Member
  • GtaGta Posts: 36Member
    Yes here is another pic
  • GtaGta Posts: 36Member
  • GordyGordy Posts: 9,264Member
    Write down what each input is set to as it is programmed now.
  • GtaGta Posts: 36Member
    Ok

    Jo-19.8
    HOT
    Cy-15
    Bp-2.0
    Nc
    Pnp
    Air
    Reg
    Cp-1.0
    Ao-19.8
    Fo-27.9
    Fl-10
    FH-36
  • GtaGta Posts: 36Member
    Gordy ... sorry never saw you other question till now .... the pump in the centre of the pic feeds the entire house .. it’s 11 runs the 12th run on the left is not used ... it loops back and is shut off . The pump against the back wall runs my bonus room 900 sq ft with 3 /300 ft runs . The pump located towards the left side of the pic runs my attached garage. 5 runs /300 ft each .

    The bonus room and the garage can and do run together if they happen to call for heat at the same time ..... or they can run separately.... I’ve always questioned this set up... it seems wrong to introduce cold garage water to the boiler when the bonus room is running
  • GordyGordy Posts: 9,264Member
    Those settings appear to be fine.
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