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Help with a balancing valve

It was suggested, by a seemingly knowledgeable person on another forum, that the issue I am having with black particles coming from the hot water taps (via the passive recirculation system) would be resolved with a balancing valve. He suggested that I ask this group my two questions:
  1. Can you recommend a specific balancing valve for me to use?
  2. Can you provide a sketch showing me how to hook it up?
Our system is very simple: water heater with ¾” lines to the taps and a ½" passive recirculation line feeding into the bottom of the water heater.



    EBEBRATT-Ed Member Posts: 13,799
    Don't know what a balancing valve has to do with black particles.
  • HomerJSmith
    HomerJSmith Member Posts: 2,266
    Some thoughts. I used a passive recirc sys on my house when I had a gas water heater. Worked great. Switching to a mod con with a indirect tank I changed to a pump sys.

    Ed's right as I see it. What might be happening is that when you turn on the faucet. the tap water flows thu the 3/4" line to the faucet and also thru the 1/2" line to the faucet. Debris from the bottom of the tank may be moving up the 1/2" line.

    You might flush the tank thru the drain valve.
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,076
    edited July 2021
    Hi @gproston , A common source of black particles is braided flex connectors. The inner rubber can deteriorate with time and shed these black bits. See if they smear on the sink. If so, and if you have braided lines to the water heater, replace them with corrugated stainless or copper flex connectors and see if the problem goes away.

    About that balancing valve, I imagine you need something to throttle the flow through the recirc line, or when you draw water, too much will flow from the bottom of the tank and affect the hot water temperature, maybe bringing sediment with it. Some folks put in a swing check valve and drill a small hole through the flap so water can slowly flow by gravity, but less will flow backwards when a tap is opened. Throttling the flow with a ball or gate or globe valve will work too. Get it set right (which can take days) and then remove the handle and tape it to the pipe, so nobody messes with it inadvertently.

    Yours, Larry
  • HomerJSmith
    HomerJSmith Member Posts: 2,266
    Larry is right. You could be getting small particles of rubber plugging the aerator on the faucet, if that's your issue.

    I have found that the rubber seals on the hot water angle stop, more so than the cold water stop, fails and the bits plug up everything that follows the valve.

    You have to make a more discriminative analysis of what the particles are.
  • hot_rod
    hot_rod Member Posts: 19,896
    Any galvanized or steel piping in the system?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • gproston
    gproston Member Posts: 2
    No rubber or steel - all copper