Watts Series 800M4QT Anti-Siphon Pressure Vacuum Breaker Cap Leaking

Discussion in 'Irrigation / Sprinkler Forum' started by rbsfam, Apr 7, 2006.

  1. rbsfam

    rbsfam New Member

    Messages:
    2
    My Watts Series 800M4QT Anti-Siphon Pressure Vacuum Breaker is leaking a lot at the cap. I think it froze up over the winter, but I removed the cap and can't see anything wrong. The cap is not cracked and all parts inside seem to be in good shape. Is it just loose and I need to tighten it? Are the parts out of alignment? I don't want to replace the whole thing because the brass parts are fine. Any ideas?
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Replace the gasket on the plunger.

    By the way, I assume you mean it is leaking when the water is turned ON. Depending on where this valve is in your system, if it is leaking when water is OFF, the the water control valve is leaking. A vacuum breaker would always dribble if there is water present at very low pressure.
  3. rbsfam

    rbsfam New Member

    Messages:
    2
    Watts Series 800M4QT Anti-Siphon Pressure Vacuum Breaker

    Thanks for the help.

    Can you tell me what the gasket looks like? I see at least two, one is black, thin, and about 3" in diameter. The other is red, a bit thicker and about 1 1/2" in diameter.

    Also, I just noticed a white plastic piece that's broken. It's just below the cap, round and has 4 posts sticking up on top. Two of those posts are broken off. The other two are fine (and they're opposite each other). Do I need to replace that as well?

    Finally, where can I find the parts?

    Thanks again, and yes, it leaks when only when the water is on.
    Last edited: Apr 12, 2006
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    valve

    Usually the "float"/poppet is cracked. And usually when it is, it is hard to see the crack.
  5. PDBS

    PDBS New Member

    Messages:
    7
    Location:
    Bellevue, WA
    This must be contagious.... I have a 6+ year old 3/4" 800M4FR and during my spring startup I also found that I have water leaking out of the cap when I turned the water on. I'd like to tackle this myself before I resort to making a service call with an irrigation company, since I might actually learn something. :)

    I took it apart and I don't see any parts that are visibly broken, so I had figured that my best bet was to replace the rubber goods (a "Rubber Parts" kit from Watts comes with a vent seal, check disc, and bonnet o-ring). I see that I can get this kit online at Kelly Supply for about $10 plus s/h. Is this something that I could also find at a local plumbing supply shop or would I be better off going to my local Watts distributor?

    hj and Jimbo, what parts did you suggest that rbsfam replace? Is the "gasket on the plunger" the Check Disc and is the "float"/poppet" the Vent Float in the diagram below?

    [​IMG]
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    valve

    The vent float and seal come as a unit. Replace it.
  7. PDBS

    PDBS New Member

    Messages:
    7
    Location:
    Bellevue, WA
    hj,

    Thanks for pointing me in the right direction.

    I tried a few different things and finally figured out why the vent float was not making a water-tight seal against the bonnet. Basically, when I turned the water on, the vent float was not gliding smoothly along the vent spring due to iron/manganese buildup on both parts from my well water.

    I took it apart again, cleaned the vent float and vent spring, and now the water flow out of the bonnet has stopped!

    I have lots of mosquito bites for my trouble, but I have a working irrigation system to show for it. :) I will talk to the guys that come to close my system this fall and see how often they swap these parts out when untreated well water is part of the equation. If I can find a local place that carries replacement parts, I may just let it last as long as it can before I do anything.

    Thanks,

    Steve
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