Pay attention to your pH

[Bad Wolf]

I always knew my water was on the acid side but had installed a soda ash solution pump that I thought was taking care of it.
Well, when I started having the storage tank overflow it became apparent that I had a pinhole leak in the HX. (150ft of ¾” refrigeration tubing) I had to drain the system twice to cut and install couplings in four different places.
I had several water treatment companies out and they measured a pH of 5.5 which is lower than I remembered. I have since installed an acid neutralizer system (broken link removed to http://www.cleanwaterstore.com/calcite-blend-neutralizer.html)
$700 for the neutralizer, a hundred dollars in parts and 3 hours and its all set. So far so good.
pH is now around 7.4

So if you see that blue-green staining in the sink, it’s the copper leaching out of your pipes

 

[BoilerMan]

Ouch Greg, is the Ref tube directly buried? How long did it take to pinhole?

TS

 

[Bad Wolf]

Not sure what you mean by buried. The coil is about 2 ft in dia 4 ft tall submerged in a 1200 gallon tank. It took about 4 years before I started having problems. Of course it was in the middle of the heating season so I had to constantly drain water off the tank. It "healed" itself after a couple of months. I think the hole just got plugged. Then it opened up again in August. Since I was only using it for DHW, I plumbed an electric heater into the system so I can bypass the storage tank. (It actually gives me the option to not have to build a fire in the summer)
Then I drained the tank and had to climb inside, with the water on I could see the jets of water. I took a small tubing cutter, cut the tube at the hole and rejoined the two ends with a coupling. Three weeks later it was overflowing again so I had to repeat the process. Now that I have the neutralizer installed I hopefully won't have the problem again.

I've also had leaks in the household plumbing over the years, but I always thought it was just bad pipes.

I think the point I was trying to make was if I had done it right 20 years ago I could have saved myself all of this aggravation.

 

[goosegunner]

That is what I do not like about coils or copper sidearm DHW heaters. Low ph water water that is softened before heated is aggressive. Combine that with continuous thermosphion like a side are and leaching is pretty likely.

Bob posted a nice set up with a buffer tank and plate exchanger very nearby. It was a on demand set up that should be very responsive.

gg

 

[jebatty]

pH of 5.5 is really low. Is this your drinking water pH? My understanding is that potable water pH between 6.5 and 8.5 is the general recommendation, and "yes," low pH is highly corrosive. Simple to test pH. Get a swimming pool test kit with pH strips. From my readings most hot water boiler mfrs recommend pH between about 8.2 and 11.0, with different mfrs having different recommendations.

 

[Donl]

Noted from the Alberta Infrastructure and Transportation "Water Treatment Program Training Manual" with regard to boiler systems:

Note: corrosion of copper material is excessive at PH levels greater than 9.5; corrosion of iron material is excessive at PH levels less than 8.5.

Given that, I would assume a PH of 9 would be optimum in boiler systems containing both iron and copper.

 

[jebatty]

I think it is a little more complicated that a simple pH of 9, although that likely is a pretty safe number. I recall that Tarm recommended 8.2, I saw a recommendation from Wood Gun which was higher than that but I don't remember what it was, and various boiler treatments have a variety of chemicals that are designed to work together, with pH then at a target level for the mix. I don't believe copper automatically corrodes with pH > 9.5 because the corrosion also requires the presence of another chemical or so.

 

[Bob Rohr]

I think it is a little more complicated that a simple pH of 9, although that likely is a pretty safe number. I recall that Tarm recommended 8.2, I saw a recommendation from Wood Gun which was higher than that but I don't remember what it was, and various boiler treatments have a variety of chemicals that are designed to work together, with pH then at a target level for the mix. I don't believe copper automatically corrodes with pH > 9.5 because the corrosion also requires the presence of another chemical or so.

Correct Jim, the ph of the fluid depends on what chemicals are blended into the glycol of treatment fluid.

A TSP bath in a new steam boiler installation, for example, will leave the water alkaline, steam boiler installers like to see that high ph. The buffers added to hydronic glycol leave it around ph 10- 11, if it drops into the ph 7 it's time to replace or add buffers. But plain water in the mid 7's ph is fine.

 

[BoilerMan]

Just a thought, if water is in the 7 range to start with, and is used to fill a closed system containing copper, steel, and stainless. No chemicals, would there be anything to change the pH? Does the natural erosion and oxygen depletion of the water continually cause the Ph to drop and become acidic, and need to have buffering chemicals added based on water tests?

BTW: This is assumeing all soldering flux and acids were flushed out with hot water prior to filling the system.

TS

 

[maple1]

I'm also kind of curious as to what happens to PH once you've sealed the system up & oxygen depletion and that other good stuff happens.

I've been neglecting a PH issue in our water here for too long. Once spring comes and I get my old oil tank out, I'm needing to re-arrange some space here for some treatment equipment.

 

[Floydian]

I needed some peace of mind on the water chemistry thing.Talking with Mike @ PrecisionChem (Wood Boiler Solutions) has given me just that. $200 for pre cleaner, boiler solution, water sample analysis and delivery for a 1000+ gallon system seems like a no-brainer to me. Hopefully running the pre-cleaner this weekend!

Noah

 

[DaveBP]

I'll second that motion, Noah. Mike has to be one of the easiest and most reassuring guys I've ever done business with.

 

[dogwood]

Noah, is this the correct site? Seems to be, but didn't see any reference to Precision Chem when it opened. (broken link removed)

 

[Floydian]

Noah, is this the correct site? Seems to be, but didn't see any reference to Precision Chem when it opened. (broken link removed)

Hey Mike! Yeah, that's the right place. Wood Boiler Solutions is an offshoot mostly to address the OWB market. PrecisionChem deals with large, industrial, institutional, etc. type systems, where, as Mike told me, you can't really show up with a name like "wood boiler solutions". Mike can send the dry versions for larger systems at a better price than the liquid versions, and of course this saves on shipping as well. Talk to him, he's great.

Noah

 

[dogwood]

Real interesting site Noah. Don't know if the water in Floyd is as hard as what we have up here in Botetourt, VA. Our well water is hard as a rock, and will likely need some treatment even after it goes through our water softener, or maybe even because it does. I've been looking around for some water treatment for a system with 1000+ gallons that wasn't prohibitive in cost due to the volume of water involved. Appreciate the tip on the dry versions of their products.

Do you know if the cleaner you purchased will do anything to clean out gunk left over from pipe-fitting. I'm sure I've got an excess of Rectorseal #5 inside some of the black iron fittings. And I'm curious if some of their product might be useful for descaling a flat plate hx too. I'll ask and post the reply. I am going to contact Bell & Gosset, the manufacturer of my flat plate hx to see what they recommend since they suggest periodic descaling.

Mike

 

[Floydian]

We had a well dug a couple of years ago and we got really lucky. 20+ gpm at 90' and when we had the water tested they told us it was as good as they have ever seen. No treatment needed but I still wanted the reassurance for my spendy heating system.

The pre cleaner will take care of oils, fluxes, etc. I believe some kind of acid is used on fphx'ers but I don't know.

I get up your way a few times a year for work and I must say, it sure is beautiful. Not that Floyd isn't, just different here up on top of our little plateau.

Noah

 

[dogwood]

You did get lucky on your well. Ours went down several hundred feet. It is nice down in Floyd too, and luckily for you not quite as populated as its been getting here. That's the Peaks of Otter in the avatar picture to the left and our view from the front door. No complaints there. Take it easy Noah. Appreciate the info.

Mike