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Banging Pipes

Ran into an unusual job this morning w/ a homeowner complaining, and rightfully so, about banging/chattering pipes after a zone shutdown on his hydronic system. The original boiler, circa 1981, was recently replaced by a Buderus G124 as well as the original Taco 545 zone valves being replaced w/ Honeywell V8043 series valves. The installation looks average w/ the pump(B&G100) on the return and of course the tank and air removal is on the supply. The system pressure of course spikes from 12#'s to 21#'s on start up due to the pump placement. My initial thought is to have the contractor put the pump where it should be, on the supply side, right after the tank/air sep/water supply but I'm also wondering about the zone valves and what role the new valves could be playing in this scenario, if any. Also, there is a Taco differential bypass valve connecting the supply main w/ the return. So what are your thought's? Also, I do have pictures of said job but don't think they're relevant.  However, I will download if anyone is curious. 

Comments

  • Check

    to see if the new zone valves were installed the correct way.  They are supposed to close against flow and could cause chattering/banging when closing with flow.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • billtwocase
    billtwocase Member Posts: 2,385
    I'd also say

    Check the zone valve body arrow for correct direction. The pump on the return will not cause that. I'd also check the end switches. There could be one that is still making when the valve is closed on the off cycle. I'd also follow all heat piping to see if there is an old zone valve or something down the line. Is the B&G new? If not, than that may not be the only corner that the installer cut.
  • Ironman
    Ironman Member Posts: 7,441
    B&G 100

    Does the system need that large of a pump? How about using an Alpha (on the supply) and eliminate the pressure bypass.



    I agree about checking the zone valves.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Scott Kohler_2
    Scott Kohler_2 Member Posts: 8
    Valves

    I think all are correct. We're going to have the contractor change the zone valves back to a similar style valve(taco 571) as well as changing the pump/tank orientation. Thanks f/ the input.
  • Scott Kohler_2
    Scott Kohler_2 Member Posts: 8
    Valves

    I think all are correct. We're going to have the contractor change the zone valves back to a similar style valve(taco 571) as well as changing the pump/tank orientation. Thanks f/ the input.
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