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Water Contamination with Black Specs

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  1. #1
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    Question Water Contamination with Black Specs

    Hi there.
    Not sure what is going here, but I noticed a load of black particles coming out of the hot water (shower and taps).

    Initially I thought could be something wrong with the head shower, but then I noticed I found the same particulate on different taps around the house.

    I have four assumptions:
    1) The hydronic panels are releasing the foreign material (read below)
    2) The Rinnai 200e (heat source) is releasing the particulate
    3) The Grundfos Pump (hydronic pump) is releasing the particulate.
    4) The pipes are corroded (I thought they were made of copper) but I have to consider that as well.

    I bought my house with the current how water + hydronic system. So apart from who installed it - there is a sticker in the pump enclosure - I don't have the plumbing diagrams that shows what was installed here.

    All I know (that is explicitly advertised on their website as well) is the hydronic loop and hot water loop are the same thing. Which adds even more complexity to this problem.

    During the reno, the panels were removed to paint the walls behind them, and we noticed that a considerably high amount of heavy particulate was coming out of the radiators while bleeding them.

    I attached two images, one with the baby bath showing the black particulate (it's metal for sure) and another one with the system architecture from the installer (I removed the company logo as I don't want to roast them here).

    To the specialists here, have you ever seen this?

    Maybe the plumbing code has changed (correct me if I'm wrong please) but I would imagine these two systems should work on separate loops (?) - Maybe this is a separate issue, but that made me think about this...

    hydronic.jpgimg_7288.jpg

    Any comment/thought would be great, I'm really concerned about this.

  2. #2
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    Rule out your hydronic, that will be a sealed loop with an air gap to avoid cross connection. Run all taps for a minute to see if it clears. Could be either crap thats come through from the mains or even a water filter may have crapped itself.
    Love it when DIYERS pin the blame on plumbers for their own shoddy work

  3. #3
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    Default Water Contamination with Black Specs

    Quote Originally Posted by plum View Post
    Rule out your hydronic, that will be a sealed loop with an air gap to avoid cross connection. Run all taps for a minute to see if it clears. Could be either crap thats come through from the mains or even a water filter may have crapped itself.
    Thanks plum. But I did not understand your statement about the sealed loop. I can guarantee you they are in the same loop here, there is cross connection for sure and I can’t isolate the hydronic.
    I’ll try your method tough


    S

  4. #4
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    CAUTION OP

    I strongly suggest you contact the design company or someone who is familiar with these systems as you may be dealing with LEGIONNAIRES due to dead legs (pipes not used very often)


    Plum

    Not about to go against your up to date expertise as I have never had anything to do with hydronic heating, but what I see in the diagram is a simple flow return hot water system which feeds through

    the radiators in each room, but is also the supply return for the domestic hot water for showers etc.

    (see box on right of pic which shows "Water flow to radiators and domestic hot water fixtures."

    So I have to believe this is all one system.

    The particles could be coming from copper pipe which is not used very often or from the radiators, so flushing the system as you have suggested, making sure all radiators and hot taps are operated for

    a period of time , is the best idea.



    OP SEE MY CAUTION

  5. #5
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    Default Water Contamination with Black Specs

    That looks like granulated carbon from a cartridge filter like my house setup pictured below.

    If you have something like this then it may have a loose fill carbon filter in the second housing that has failed...
    Joined RF in 2006...Resigned in 2020.

  6. #6
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    The particles look like corrosion from copper within the system (disclaimer - I am not an expert). What is the source of water used in your house? Rainwater is becoming increasing corrosive in copper pipes due to the rise in atmospheric CO2. I solved corrosion problems in a previous house running rainwater by dropping limestone rocks in each tank which raised the pH from 6.2 to 6.8. Desalinated water is also corrosive in copper plumbing unless it is re-mineralised.

    Edit: acidic corrosion increases as temperature increases, so I would expect corrosion will appear in hot water circuits first.
    Before you speak, ask yourself: Is it necessary, it is true, does it improve on the silence? - Baba

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    Thanks SilentButDeadly, but my house is not fitted with any filter.

  8. #8
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    Water is coming from the main water supply, from Yarra Valley.
    You gave me a good idea now, I should check the first tap just after the meter, and see if there are particles coming from there.

    Quote Originally Posted by John2b View Post
    The particles look like corrosion from copper within the system (disclaimer - I am not an expert). What is the source of water used in your house? Rainwater is becoming increasing corrosive in copper pipes due to the rise in atmospheric CO2. I solved corrosion problems in a previous house running rainwater by dropping limestone rocks in each tank which raised the pH from 6.2 to 6.8. Desalinated water is also corrosive in copper plumbing unless it is re-mineralised.

    Edit: acidic corrosion increases as temperature increases, so I would expect corrosion will appear in hot water circuits first.

  9. #9
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    It is all in one system. Guaranteed.

    I took the Hydronic enclosure cover off and check this out (check all images, they are from looking downwards to upwards, towards the boiler).



    It is a one loop system for sure.


    Quote Originally Posted by cyclic View Post
    CAUTION OP

    I strongly suggest you contact the design company or someone who is familiar with these systems as you may be dealing with LEGIONNAIRES due to dead legs (pipes not used very often)


    Plum

    Not about to go against your up to date expertise as I have never had anything to do with hydronic heating, but what I see in the diagram is a simple flow return hot water system which feeds through

    the radiators in each room, but is also the supply return for the domestic hot water for showers etc.

    (see box on right of pic which shows "Water flow to radiators and domestic hot water fixtures."

    So I have to believe this is all one system.

    The particles could be coming from copper pipe which is not used very often or from the radiators, so flushing the system as you have suggested, making sure all radiators and hot taps are operated for

    a period of time , is the best idea.



    OP SEE MY CAUTION
    Attached Thumbnails Attached Thumbnails image02.png   image03.png   image01.png  

  10. #10
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    How does the hot water in the first picture pipe 'D' get to the heater in the second picture with the circulation pump, which is driving the hydronic heating? Or does pipe 'D' go to the second bathroom and laundry?
    Before you speak, ask yourself: Is it necessary, it is true, does it improve on the silence? - Baba

  11. #11
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    When the circulation pump is ON, it moves the water from the Pipe E to the boiler (it goes up in the picture), forcing the water to flow around the whole hydronic system. At the same time, the hot water coming out of the boiler finds its way to the pipe D (down in the picture). This is how the water flows in these two pipes.

    Just look at E and D pipes, ignoring all the rest, it will be easier to understand. I hope I clarified.

    Cheers.

    Quote Originally Posted by John2b View Post
    How does the hot water in the first picture pipe 'D' get to the heater in the second picture with the circulation pump, which is driving the hydronic heating? Or does pipe 'D' go to the second bathroom and laundry?

  12. #12
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    So picture 1 joins under picture 2?
    Before you speak, ask yourself: Is it necessary, it is true, does it improve on the silence? - Baba

  13. #13
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    Default Water Contamination with Black Specs

    Quote Originally Posted by John2b View Post
    So picture 1 joins under picture 2?
    Yes


    S

  14. #14
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    Quote Originally Posted by cyclic View Post
    CAUTION OP

    I strongly suggest you contact the design company or someone who is familiar with these systems as you may be dealing with LEGIONNAIRES due to dead legs (pipes not used very often)


    Plum

    Not about to go against your up to date expertise as I have never had anything to do with hydronic heating, but what I see in the diagram is a simple flow return hot water system which feeds through

    the radiators in each room, but is also the supply return for the domestic hot water for showers etc.

    (see box on right of pic which shows "Water flow to radiators and domestic hot water fixtures."

    So I have to believe this is all one system.

    The particles could be coming from copper pipe which is not used very often or from the radiators, so flushing the system as you have suggested, making sure all radiators and hot taps are operated for

    a period of time , is the best idea.



    OP SEE MY CAUTION
    Certainly have more knowledge of the older hydronics which had header tanks to top the system up with a physical air break. It appears this system has non-return valves, like a reduced pressure zone valve to stop heating water entering the domestic hot water supply.

    As you suggest, best the experts look at this.
    Love it when DIYERS pin the blame on plumbers for their own shoddy work

  15. #15
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    Default Water Contamination with Black Specs

    Long time since my last post, but between my first post and today I have not only trying to make a positive contact with the company that supplied the system but trying to find a plumber experienced on this system. I failed badly ��

    Firstly, I am convinced this system is a lemon.

    I contacted the system seller, but I could not get too far. According to them the system is watermark as all hardware supplied is copper. But himself advised me to flush/clean the system every year (it cost $700 per year). So I failed to follow his logic! If the system is really clean why bother flushing it every year? I gave up. The guy over the phone was rude and he was blaming the main water service for the gunk.

    I got VBA onboard as well to seek some help, they were extremely helpful but they could not find who actually installed the system. So even we know who supplied the system there is no document showing us who installed this crap here.

    So at the moment I’m fully convinced that I need to split this system in two and move forward.

    To achieve that i will be installing a 2nd heating unit/boiler and split the system. The only issue is ensuring the water service is now fully isolated from the old hidronic loop. But I reckon any experienced plumber can do that. At the moment under my bathroom floor there are some dodgy plumbing happening as my local plumber could not isolate the loops.

    Thanks for all suggestions and I’ll keep posting


    Sent

  16. #16
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    Suspect the supplier to be H****T**** and the system classed as G****H***.
    If you check the temperature at the hot water kitchen tap it will give you an indication at what the rinnai unit is set to.
    The bathroom & ensuite, being ablution fixtures, should have temperature of no greater than 50 degrees C.
    The only way to achieve this in a system of this nature is with tempering valves.
    Therefore the presumption is that one is fitted somewhere along pipeline 'C' in pic 1 of #9.
    If the bathroom tees off from 'D' (flow line) then an additional tempering valve would be necessary.
    If the entire system is constructed from copper with welded (silver soldered) joints, then the particulates may well be carbon deposits from the welding process.
    If this is the case, then in hindsight you should have flushed out the panels before reinstalling them.

  17. #17
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    I assume after this time the particles have stopped?
    Any low flow system like the hydronic heating will build up some settlement over time especially if not flushed properly initially. Even on town water it can be surprising what comes through.
    Since it's a common system using the same boiler when you disturbed it there has been some contamination of the hot water lines.

    My Old man's system is pretty similar but the equivalent to line "E" has a T off and a drain valve to give it a flush/remove air.

  18. #18
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    Hi. correct.
    Rinnai is set to 65. And all taps and showers got hot water temp at this temp. Kids bath time is a nightmare for me as I need to supervise them all the time. The only good thing is having lava hot water at the kitchen to wash off grease and roasting trays.


    Quote Originally Posted by RodEye View Post
    Suspect the supplier to be H****T**** and the system classed as G****H***.
    If you check the temperature at the hot water kitchen tap it will give you an indication at what the rinnai unit is set to.
    The bathroom & ensuite, being ablution fixtures, should have temperature of no greater than 50 degrees C.
    The only way to achieve this in a system of this nature is with tempering valves.
    Therefore the presumption is that one is fitted somewhere along pipeline 'C' in pic 1 of #9.
    If the bathroom tees off from 'D' (flow line) then an additional tempering valve would be necessary.
    If the entire system is constructed from copper with welded (silver soldered) joints, then the particulates may well be carbon deposits from the welding process.
    If this is the case, then in hindsight you should have flushed out the panels before reinstalling them.

  19. #19
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    Actually no. The system was pretty much turned off since October since the temperatures went up a bit in Melbourne.

    Interesting enough, on Sunday I was staring at this crap system, I had the idea to test if that check valve was doing its job.

    I've shut the valve A (hot water service) and tested if the hot tap would have any water.
    image01.png
    Looking at the below diagram, the check valve should not let any water flow back following the blue arrow, but for my surprise, the hot water tap was still flowing water suggesting the check valve was not working.
    image02.png
    The amount of crap that came out of the tap was amazing. I had to remove the aerator otherwise the were no flow. I let the water running for long time and it did flush a lot of crap.

    I removed the check valve and noticed the flap was indeed stuck - always open...I cleaned the flap shaft with a natural degreaser I had here around and the flap is now working as designed.

    We had several occasions of not having hot water (just lukewarm) and that was the issue, was the check valve letting cold water mixing with how water....

    Anyway, interesting trouble shouting and something to keep me busy during the lock down.

    For anyone thinking about this system, please stay away. There are so many design flaws and the failure mode impacts directly on your family health.

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