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Ragu Member Posts: 138
Was wondering how you guys handle antifreezed hydronic systems. SOP for me has been to power purge the system, shut off the feed and remove the valve handles, TAG the system, return to the job several times during the first few weeks to check system pressure drop and add more glycol if needed, then test and document for concentration of solution. Finish with informing customer that system needs annual maintenance to include concentration and pH test. Do many of you pipe in a pressurized glycol tank? Was wondering about liability re: depending on LWCO?


  • Ken_8
    Ken_8 Member Posts: 1,640
    I only have a few

    snow melt and/or unique systems with glycol but never cease to be amazed by the corrosion created by the inhibitor when they get 2 or 3 years old.

    The solution seems to be much better when we TSP a system and rinse it - THEN put the glycol in. We have found the cost of the glycol has little to do with its going "bad." The cleanliness of the system is key.

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  • hr
    hr Member Posts: 6,106
    I'd agree

    with Ken in that the cleanleness of the system is critical to glycols longevity and performance.

    Also the blend water is very important. If you use hard water, excessivly high or low ph out of spec TDS numbers, etc you end up using the inhibitor package in the glycol up. Then it has little if any protection left, from day one!

    Glycoled systems should be checked yearly and buffered with an inhibitor doseage if needed.

    I know two companies that have put a sample of various brands of glycol on a shelf with a nail and a piece of copper in the glass.

    Yes, there is a huge difference in outcome. The less expensive glycols have less inhibitors! It's a classic you get what you pay for.

    Nobel, Dow, and Herculeas are brands I trust to be properly formulated. Good factory support for testing also.

    I'd use glycol only when absoutely necessary. Expensive, messy, maintenance prone, and requires careful attention to pipe, pump, and expansion sizing. My experience shows it leaks from the smallest of openings. Iso flange packings, air vent crimps, ocassionally o ring seals on Spiro or Honeywell air purgers, etc.

    If it is a large system consider a glycol fill system. Axiom is one brand, and I believe B&G just introduces a small system. BUT, be sure you don't have any leaks before you add an auto fill glycol system :)

    hot rod

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  • Ragu
    Ragu Member Posts: 138
    Ice Storm

    We had an ice storm here about 5 years ago in January. No power for 2-3 weeks. Many, many houses froze up, especially those where the owners went away for the winter, but kept the heat on. Most places weren't piped for easy draining. Lots of antifreeze requests since then (also lots of generator installs). Tough call, because it WILL leak. I think it's a trade off.
  • hr
    hr Member Posts: 6,106
    It might be better

    to check into freeze alarms for those that are gone during cold periods.

    All the glycol in the world, in the heating system, will not protect the potable water piping in a house :)

    Most of the second, or vacation homes, we worked on had central alarm for security. These all had freeze stats under the kitchen sink, and often in the mechanical room. The alarm company would respond to "cold" calls and notify the contractor.

    hot rod

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