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Pipes bang when zone valve closes

Zone valves are in the return flow, installed correctly, pump flow in proper directions. Any chance that a new zone valve would correct this?

Comments

  • phil Kriesel
    phil Kriesel Member Posts: 3
    How to trouble shoot

    I have one zone in my house, the house has 3 zones, that bangs sometimes when the zone valves closes. Could it be air or a problem with the zone valve. I have tried to add clamps to restrain the pipes which is not helping. thanks for any help.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,425


    > I have one zone in my house, the house has 3

    > zones, that bangs sometimes when the zone valves

    > closes. Could it be air or a problem with the

    > zone valve. I have tried to add clamps to

    > restrain the pipes which is not helping. thanks

    > for any help.



    Retired and loving it.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,425


    > I have one zone in my house, the house has 3

    > zones, that bangs sometimes when the zone valves

    > closes. Could it be air or a problem with the

    > zone valve. I have tried to add clamps to

    > restrain the pipes which is not helping. thanks

    > for any help.



    Retired and loving it.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,425
    This should help:

    Banging Zone Valves
    Retired and loving it.
  • Paul Fredricks_3
    Paul Fredricks_3 Member Posts: 1,552


    You might also check that the zone valves are installed the right way. There should be an arrow on them showing the direction of flow. I have found in the past that were installed backwards.
  • bob young
    bob young Member Posts: 2,177
    check direction of flow

    pump could be reversed making zone valve slam shut.
  • Rob_35
    Rob_35 Member Posts: 33
    suggestion

    Not a pro with any experience, just a fairly well-read HO. Thoughts.

    1) different zone valves might help. Ask an experienced installer what they would recommend. All zone valves are not created equal.

    2) see what kind of circulator you have on the system now, and look at it's pump curve. So-called "flat-curve" circulators work better (at least in theory) in zone valve systems. Taco has a nice technical data sheet on this. Rummage around their file library for "understanding pump curves" or similar.

    3) consider going to an all-circulator system and dump the zone valves. One downside of this approach that I learned on this site is the "parasitic energy consumption" (e.g., using 2-3 pumps when 1 would do the job) goes up. Zone valves use a lot less electricity than a circulator (at the moment. I understand new super-efficient pumps from WILO and others are coming.)

    Good luck.
  • Dennis
    Dennis Member Posts: 98
    Secure the piping with more clamps,

    install a pressure bypass valve. Do this check, see if the banging occurs when two zones are calling, and one of the zone valves closes. If this is the case, you need a bypass.
    One last idea, if the circulator has a shut off valve on the discharge side close it half way, see if this solves the problem. If closing the valve half way causes the house to heat improperly, open it a little at a time until the house heats properly. If this solves the problem, install a smaller horse power pump at the next change out.
    How to figure your pump head; measure the longest run in feet (one zone the longest) add 50%, multiply by .4, this number is the pump head needed.
    Just do it, right.
  • Leo
    Leo Member Posts: 767
    If you have

    If you have Honeywell zone valves they have been known to do this. They have been redesigned to eliminate this problem.

    Leo
  • mark schofield
    mark schofield Member Posts: 148
    expansion tank?

    would a waterlogged expansion tank have any effect on this problem. like a water hammer in a DHW loop if the expansion tank is waterlogged.
  • Flip
    Flip Member Posts: 40
    zone valve noise

    we've had some problems with Honeywells making noise. removed one of the two return springs to slow the closing time. they were much quieter.
  • tim smith
    tim smith Member Posts: 2,397
    zone valve banging

    Just met w/ Honeywell products rep last week, if it is a Honeywell, they have a new operator designed to slow close to help that problem. It will fit on the older model zone valves. Pretty slick new design. Good luck, Tim
  • phil Kriesel
    phil Kriesel Member Posts: 3
    Erie zone valves

    The zone valves are erie. Would taco slow close work better?
  • Plumdog_2
    Plumdog_2 Member Posts: 873
    check that formula

    seems like a mighty high head would result.
  • Jed_2
    Jed_2 Member Posts: 781
    Not- Very- Reliable-Dennis

    With that kind of advice. Try .04.
  • been using

    Been using taco zone valves, never had plms with them, wish they make the same 571 valve with dry end switch...
This discussion has been closed.