water quality in a closed system

Tman

any thoughts? I have a snowmelt system with a Laars Mighty Max boiler that's using a flat plate heat ex. to separate the glycol side of the system. The problem is that the inlet strainer on the water side of the heat ex. was plugging up with a pastey muck. I took a sample of the muck
to a lab and had it tested and the report said it was abundant copper and iron. I've had to clean out the strainer about 8 times and it is better now but there's a lot of material still in the water. I've checked the boiler pump and it's velocity is 8.5 ft/sec. The system was put in last year and according to the homeowner it worked great. I did a fall check of the system before this winter and found
the "muck" problem. Any opinions on if I have a water quality problem or a velocity problem? Thanks

Mark Eatherton1

What

is the pH of the fluid?

If the system is seeing 8.5 f.p.s., it could be that hydrolysis is eating your pipes. If the pH is too low, the fluid cold be eating your pipes. If the fluid pH is low AND your velocity is high, the system as a whole is going to eat your lunch:-)

ME

Ted_5

Check with HeatLink

as company they are making a stand on Water quality or the lack of in 90% of the systems out there!!! They are offering a line of test kits, treatments and the first radiant floor company that offers a sidestream filter for your system. Check into it.

Ted

hr

The answer is always

in the water or fluid quality. Ph is the important and easiest to check indicator. Glycol has other tests needed.
Sounds like the fluid is attacking and disolving the components of your system. A good flush, cleaning, and refill with conditioner may be needed to get back to solid ground, or water

hot rod

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Tman

water quality in closed loop

Thanks for responding. The ph is 6.92. When I called Laars they said they wanted a slightly acidic ph to keep bacteria down and when I asked him what they were looking for specifically he looked it up and said 7.2-7.8!! Laars spec'd the pump for this job and I'm getting the feeling they're making me jump through hoops to avoid liability.
All I'm looking for is a solution so I can take care of my customer and give him the quality system he's paid for. This has been dragging on for the whole winter and now it's warming up and I still don't have a definitive answer.
Any help would be greatly appreciated. Thanks

hr

Not following that logic

You won't or cannot have bacteria without a food source. This is the purpose of a good cleaning and flush with a cleaner made to dissolve oil, grease, flux etc. THIS is the foor source. Bateria exisits everywhere. but it has to eat.

So flush out that gunk you mentioned, add a cleaner, run for a few days and flush that. Then add a conditioner to plate, scavange O2, balance ph, etc.

The ph when you use hydronic conditoiners will run more in the 8-9 range. Glycolledsystems more like 9- 10.5 as the inhibitors will raise the ph level.

Equally importantis to use good blend water, or else you will ruin the inhibitor package in the chemicals. Hardness is a critical number to warch with blend water.

Copper tube boilers like glycol below the 50% mix. Generally 35-40% of a good brand of hydronic glycol will protect for freeze and inhibitors. Don't go below 30% glycol without beefing upo the inhibitor package. The inhibitors in glycol are there to handle the blend water moreso than the glycol component.

You have some work to do! It not tough, but will require a few trips and some testing to get it right.

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George_10

We can help

Give me a call at 800-543-5975. We have the solution to your problem for cleaning and treatment. The two products were specifically formulated for closed loop systems.

George Hunt