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DHW Circulator making bubbling sound?

rynoheat
rynoheat Member Posts: 9
in Domestic Hot Water

I have a System 2000 EK1. I backflushed the plate heat exchanger today(it was pretty gunky) and then flipped the power switch back on. If there's no call for heat on power up, the manager runs the circulator for a minute or so. During this I realized I hadn't reopened up the valve below the DHW circulator. I'm not sure if the manager runs the DHW circulator during this process, but if so, I ran it dry for about 30 seconds.

I ran some hot water to force a call, just to make sure everything is working. Now it seems like the DHW circulator is making more noise than before. It kind of sounds like rapid little bubbles, or a quiet teakettle. It's quiet enough that I'm doubting myself - maybe it always made that sound.

It's still pumping well enough to heat the tank in a reasonable time, but I'm wondering if I should be worried about it failing. It's a Taco 006-BT4.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 24,556

    Probably air in the system… purge it.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rynoheat
    rynoheat Member Posts: 9
    edited November 8

    How do you purge that side? The only way I can think to do that would be what I did to backflush it already.

    Here's a diagram of how it's setup:

    exchanger diagram.png

    It seems like the way air should get out is through the house hot water, and I've already run a lot through it.

    EDIT: Circulator is not on that diagram, but it's between the valve and the purple spigot

  • Jamie Hall
    Jamie Hall Member Posts: 24,556

    You might think. But two problems: You need 5 gpm at least to purge — and I doubt that the circulating pump manages that. And second, in your setup the flow is downwards — and the air bubbles don't like going down.

    It may go away with time.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Roger
    Roger Member Posts: 363
    edited November 9

    Thank you for everyone’s posts.

    @rynoheat, backflushing is one of the primary ways you can get air are out of the domestic hot water side of the heat exchanger. It sounds like you’re doing that already. As @Jamie Hall noted, minor air sounds may go away with time.

    This link has more details on hot water setup and diagnostics if you are interested; refer to pages 17 through 20.

    https://energykinetics.com/wp-content/documents/hot-water-tanks/installer-manual-tanks.pdf

    Best,

    Roger

    President
    Energy Kinetics, Inc.

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