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Weird corrision leaks on a 2 year old system?

I'm having some minor corrosion leaks on my 2 year old closed loop hydronic radiant system. Some of you may remember me from this thread:
http://forum.heatinghelp.com/discussion/150929/poor-radiant-floor-hydronic-installation

The good news is that the poor installation was fixed, but now I have some weird leaking brass valves, pump isolation flanges and dielectric unions (see pictures).

I' wondering if it's dielectric corrosion or something else, i.e. acidic water in the system. Checking the closed loop water showed concerning low pH Levels. I also found a corroded circulator bolt/nut (maybe a zinc nut!!) which is concerning.

After I removed the pump with the corroded bold the system suddenly stopped leaking. I'm completely puzzled.

Any tips or comments what could be going on?

Thanks,
Sam






Comments

  • kcopp
    kcopp Member Posts: 3,787
    Is there glycol in the system?
  • samsimg
    samsimg Member Posts: 4
    No, just plain water. I rinsed the system after the contractor rebuilt it last year.
  • kcopp
    kcopp Member Posts: 3,787
    The Dielectric union looks just like a simple leak. I like tape and dope on threads. That looks like blueblocker alone. I prefer a soft set dope.
    The other drips are more mysterious. I would start w a water test. Is there any non barrier tubing in the system?
  • hot_rod
    hot_rod Member Posts: 14,879
    Did it ever have glycol in it? That looks exactly like seeps common with glycol
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    SWEISteve Minnich
  • kcopp
    kcopp Member Posts: 3,787
    I am going to sound like a broken record but... I would flush and clean the system w a good Fernox of Rhomar product then add a good inhibitor. Water quality is everything in these newer systems.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,217
    kcopp said:

    The Dielectric union looks just like a simple leak. I like tape and dope on threads. That looks like blueblocker alone. I prefer a soft set dope.
    The other drips are more mysterious. I would start w a water test. Is there any non barrier tubing in the system?

    I agree.

    The leaks in the iso flange and the purge valve, I could almost guarantee are the result of overheating while soldering. Those valves are threaded together at the leak point. It is fine thread sealed with locktite. If you get it to hot you compromise the seal and it leaks. Only way to fix it is to disassemble it and reseal the threads.
  • samsimg
    samsimg Member Posts: 4
    Thanks everyone for the replies. This is really helpful.

    I ordered a Fernox express boiler commissioning kit with cleaner and inhibitor. I wanted to add corrosion inhibitor anyway...

    With the kit I also got some pH test strips. My current water in the closed loop is acidic with a pH of 4. Any idea why this happened?

  • hot_rod
    hot_rod Member Posts: 14,879
    That is a very low ph number, was that a test strip check?
    What is your tap water ph?

    Sounds like an acid based cleaner may have been used and not flushed out completely.

    A good cleaning then fill with water with low TDS, you may need to haul water or run yours through a DI unit.


    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Solid_Fuel_Man