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Flowchecks in primary loop

jim lockard
jim lockard Member Posts: 1,059
No Need.your not checking anything just feeding the loop.j. Lockard


  • Marty_11
    Marty_11 Member Posts: 7
    Flowchecks in primary loop

    I had a call for a water leak. Apt building, two boilers
    primary/secondary piping. Each boiler has pump on feed
    riser, pushing into primary loop. Out of circ is short nipple, elbow, 8' nipple flowcheck. (2") black iron.
    Both flowchecks are rattling, one has beat itself to death
    and leaking from top, other is on its way out. I have talked to a few techs with more experience than myself, and
    get mixed ideas on what is wrong here. Some feel the flowchecks are too close to the elbow but one fairly experience tech suggested that there is no need for flowchecks in the primary loop. Any advise here would be much appreciated.

  • flow checks on both boilers

    ARE needed on the BOILER pumps. Otherwise when one boiler is running it will be making the resting boiler hot too.

    Did the previous person use flow check or SWING checks?

    What size boiler lines do you have? What size header? Do your boilers go up to a header that tees into a primary loop?

    What BTU rating is on each boiler?
  • Marty_11
    Marty_11 Member Posts: 7
    Flow checks

    One boiler is a slant fin, fired 1.65, the other boiler is a crown fired 2.50. Both are connected to the end switch of a multizone relay. Both pumps run on a call for heat. The slantfin is set to fire if temp is below 150, crown 180.
    Crown runs majority of time. The primary loop is 2", the feeds of both boilers are tied together, the zone circs are on the returns, building is split up using taco zone valves.
    I have one vote that they are needed, one that they are not.
    Guess I am going to wait and average the votes out. If I can provide any more information, let me know.
  • lchmb
    lchmb Member Posts: 2,997
    dump them

    Think you'll find you have no need for them Marty. IMHO..
  • hr
    hr Member Posts: 6,106
    With one boiler off

    does it get warm? If so you have flow through the unfired boiler.

    There really is no harm in having a check, or better yet circulators with intergral checks.

    Hard to say with your installation without seeing a drawing or picture. Not all P/S piping is created equal.

    hot rod

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    EBEBRATT-Ed Member Posts: 15,329

    Usually they are not needed but may be required depending on the piping. You say"both boiler supplies are tied togeather" This tells me you may need them. With different boilers (and possibly???different pumps) you could have pumps with different head/flow requirements.

    If the idle boiler gets hot when not firing you need them.

    If the boilers were tied into the loop independantly of each other you wouldn't need them.

    I ko this is clear as mud. Can you post a picture or a sketch???

  • Marty_11
    Marty_11 Member Posts: 7
    Checks on primary loop

    I'll try and post a drawing when I get a minute, but will
    need some advise on how to do that, if its even possible.

    Thanks for the help

  • L'town radiant
    L'town radiant Member Posts: 36
    drawing a piping plan

    I find the easiest way to draw a simple piping plan is to use Microsoft "Paint". This is a simple drawing program that comes with any computer (often found in the "Accessories" folder) You can then save your drawing and post it for all to see!
  • zeke
    zeke Member Posts: 223

This discussion has been closed.