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Circulator

amhplumb_2
amhplumb_2 Member Posts: 62
in THE MAIN WALL
Thanks Mike T., Tony, & Weezbo! After I completed a proper sizing of the system, the 003 Taco was more than adequate! It's purring like a kitten and the water is hot throughout the house. I must repent for not looking past the boiler room, but I have never saw a DHW re-circ that small! Fortunately the customer was a friend, so it was cheap education for me! Thanks again guys!

Comments

  • amhplumb_2
    amhplumb_2 Member Posts: 62
    B&G Circulator Question

    Fellow Wallies, Has anyone had any problems with B&G’s NBF 22 bronze circulators recently? (Note: About a month or so ago there was a thread regarding issues with some model B&G which I can’t remember. Could it have possibly been regarding the NBF 22?) In my case today, I re-activated a DHW re-circulating system in a large single family home. The main issue was the swing check valve was seized shut. I replaced it with a spring loaded check, and thoroughly flushed out the lines. The owner asked me to replace the circulator as well (an old Grundfos!) The B&G NBF 22 was comparable, so I installed it. Worked great water circulated properly, customer elated there was hot water in three seconds at the kitchen faucet! Two hours later I get a call that the pump is making a loud noise. When I arrived it sounded like a machine gun firing! I turned the power off, re-started, same thing! Water was still circulating in spite of the noise, amp draw was normal. My supplier told me this was the first time they had heard of this happening, and he replaced it with a new one. This one began making the same noise ninety minutes after I installed it! Any thoughts? I have used these several times over the years and haven't had any problems. Fortunately the customer is a friend and is being patient!
  • Empire_2
    Empire_2 Member Posts: 2,340
    City water or well water?

    Something tells me that you may have a cavitation problem here. Oxygen laden water which may explain the seizing of the swing check. Might also be some kind of debris in the line near the pump. If you have isolation valve on both sides of the pump, Which would be nice, close them down and see if the pump will repeat this noise. If not, I would look elsewhere in that loop.

    My .02

    Mike T.
  • Tony_23
    Tony_23 Member Posts: 1,033
    What size pipe ?

    Why do you need a 22 ? A smaller capacity circ may be the answer. You're only trying to keep the water hot in the loop, not heating a space. Maybe you need a wye strainer ? Something must've caused the swing check to seize up.
  • amhplumb_2
    amhplumb_2 Member Posts: 62


    Mike T. & Tony, I tried closing the valves and it quiets down immediately! It's city water by the way. I think the problem is in the new check valve. I held it after I turned the valves back on. I also agree with Tony that the new circulator could be too big. I should have compared the pump curves, the old Grundfos and the new B&G! But just shooting from the hip, I re-collect that the Grunfos had more head, but don't quote me on that! I'll let you guys know! Thanks, Al
  • Tony_23
    Tony_23 Member Posts: 1,033
    Yup

    Closing the valves WILL make it quiet, it's not moving anything :)

    How about just restricting the outlet a bit ? You really don't need much flow in a recirc line.
  • Empire_2
    Empire_2 Member Posts: 2,340
    Tony, Good call.....

    The only reason I asked to valve off is to see if the sound was mechanical in nature. I agree that the pump itself may be the problem, especially if over sized and the like.

    Mike T.
  • amhplumb_2
    amhplumb_2 Member Posts: 62
    Circulator Too Large. Confirmed Tony.

    In my spare time last evening,(ha-ha, because the customer was a friend and patient), I finished a sizing and the circulator is about three times what is needed! I am going to try to find something smaller! Any suggestions? Note: After talking to the previous building owner, the old circulator was always noisy, that's why they turned it off in the first place! No flow probably caused the check valve to sieze up. The original circulator is too large. Thanks for the help guys. Sometimes we need and objective opion to see the obvious!
  • Tony_23
    Tony_23 Member Posts: 1,033
    How much head ?

    There are 5 B&G circs with lower flow than a 22.
  • Weezbo
    Weezbo Member Posts: 6,232
    maybe that the circ is seeing air ahead of it or is piped hard

    90 by hard 90,on the flat off of a riser.. that causes it to work its "head" off :)

    is someone handing you a weighted check? lose the clapper in the check you have and test it out.....check the faucets... same old tune 6?

    then it likely some problem with the circ impeller,now.

    one last thought, does the hot water have a small steamer in the field as a point of useage water heater?

    ever use a bronze body 003 1/2" sweat?

    how about gravity flow recirc?

    B&G 8 or 9W?
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