Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Radiant in-floor - Sludge, full reservior, glycol

Taurk
Taurk Member Posts: 1
Hello,

I have a radiant in-floor heating system that we installed when the house was built new 6 years ago. I noticed water coming out of the vent pipe coming off the boiler and when I started looking to cause, I found a lot of sludge building up in the vent trap. Upon further investigation, the reservoir that holds the glycol is FULL; it wasn't 6 months ago during the summer months.

The system is still keeping my basement and garage at temperature, but I'm quite concerned with these symptoms. Any ideas on what would cause the reservoir to fill up? Sludge? Related?

Thank you in advance for thoughts and ideas.
Scott

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    Reservoir? Vent pipe? Vent trap? eh?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • SuperTech
    SuperTech Member Posts: 2,152
    Reservoir for glycol? Do you happen to know the model of the boiler? Pictures would be helpful. 
  • Zman
    Zman Member Posts: 7,569
    Some pictures would help. I have seen setups where they pipe the relief valve back into the glycol pig. That would explain your symptoms.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    kcoppSuperTech
  • hot_rod
    hot_rod Member Posts: 22,114
    A few things that cause glycol to go bad or sludge, overheating on a regular basis, and exposure to air, oxygen really.
    Non barrier tubing of any type can ruin glycol quickly.

    Glycol really needs to be kept in a sealed air tight container to prevent the inhibitors from breaking down.

    One last think is putting glycol in a dirty system causes it to deteriorate quickly also.

    If all three of these condition exist, glycol can turn on you in a few months time. A yearly ph test will let you know when it is going south.
    Some pics would help
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • KNPV_PSD
    KNPV_PSD Member Posts: 3
    hot_rod said:

    A few things that cause glycol to go bad or sludge, overheating on a regular basis, and exposure to air, oxygen really.
    Non barrier tubing of any type can ruin glycol quickly.

    Glycol really needs to be kept in a sealed air tight container to prevent the inhibitors from breaking down.

    One last think is putting glycol in a dirty system causes it to deteriorate quickly also.

    If all three of these condition exist, glycol can turn on you in a few months time. A yearly ph test will let you know when it is going south.
    Some pics would help

    Sorry to bring this back from the archives, but it covers exactly my question...when using an automatic glycol reservoir should the reservoir glycol be changed out routinely? Or just keep straight H2O in it since it will be a minor amount?
  • hot_rod
    hot_rod Member Posts: 22,114
    KNPV_PSD said:

    hot_rod said:

    A few things that cause glycol to go bad or sludge, overheating on a regular basis, and exposure to air, oxygen really.
    Non barrier tubing of any type can ruin glycol quickly.

    Glycol really needs to be kept in a sealed air tight container to prevent the inhibitors from breaking down.

    One last think is putting glycol in a dirty system causes it to deteriorate quickly also.

    If all three of these condition exist, glycol can turn on you in a few months time. A yearly ph test will let you know when it is going south.
    Some pics would help

    Sorry to bring this back from the archives, but it covers exactly my question...when using an automatic glycol reservoir should the reservoir glycol be changed out routinely? Or just keep straight H2O in it since it will be a minor amount?
    Glycol should always be stored in a closed, sealed container according to Dow and other manufacturers.

    Those fill tanks to my knowledge are not sealed air tight.

    So oxygen gets to the glycol and consumes some of the O2 scavenger inhibitor.

    Of course if the system never takes on additional fluid, not much worry.

    Certainly no harm in testing, or replacing the fluid every few years. A couple gallons??

    Test the system fluid while you are at it, the Ph will tell if the fluid is going bad.

    You can buy boost kits for hydronic glycol if the Ph hasn't slipped too much.

    Any water that could get added will lower your freeze protection. May as well test that also. I like the refractometers better then floating ball type or color strips to get an exact protection number.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    KNPV_PSD
  • KNPV_PSD
    KNPV_PSD Member Posts: 3
    Correct, the tank is vented to allow the pump to draw from it. I figure that if the system is running correctly it won’t be adding any significant amount from the reservoir. I have a refractometer so I’ll just check it every season. Thanks for the help.