My Garn Corrosion Fiasco Part 1

[brad068]

Local hospitals are installing copper fixtures of some sort in hospital rooms to aid in fighting micro-organisms, and the "leaching" would be air-borne copper molecules or ions. Copper kettles have been used for a very long time and their sanitation effect through killing bacteria is well known. Might not hot water moving/eroding through copper pipes have the same result?

Yes, a relative of mine is on the forfront of this application. They are copper coating door handles, railings, etc. Anything that humans touch.

They where highlighted on a history channel program a few years ago.

 

[jebatty]

No comment on the validity or effectiveness of this method of using copper ions to control biological corrosion in hot water boilers, so FWIW: Copper - Biological Control.

A very quick scan of some material indicated that some biocides might be detrimental to plastic piping. For those interested, one *oogle search is "copper biocide boiler," and I am sure there are other keywords that would produce results of interest. Copper in marine systems is a different animal from copper in fresh water systems.

 

[Corey]

Interesting thread. I don't deal with boilers specifically, but do some work with metal corrosion. It strikes me as strange they only required one water sample and was OK to just walk away from in the spring?

As others have posted, you need high pH and low oxygen to keep the system happy and corrosion free. But these factors are always in a state of change. If you happen to have microbes in the system, their growth and byproducts can change the pH/O2 levels. If the initial fill/treatment didn't kill the colony 100% it will be back. Also, having a large exposed water surface area can allow CO2 / O2 absorption from the air - further lowering pH and raising O2. The fill water source will also have some impact. Well or spring water may tend to have more biological content than treated/city water - don't know if that was a factor or not. I also don't know what all factors were examined in the water test, but iron, sulfur, nitrogen, etc in the water are good bacteria food, so if you had notable levels, that could go to creating good breeding soup as well.

Either way, hope you have it resolved. I'd say keep up with the full spectrum of testing at least until things seem to stabilize. The big key with water treatment - if you are not ahead of the curve in keeping things corrosion free, you are behind it.

 

[steam man]

No comment on the validity or effectiveness of this method of using copper ions to control biological corrosion in hot water boilers, so FWIW: Copper - Biological Control.

A very quick scan of some material indicated that some biocides might be detrimental to plastic piping. For those interested, one *oogle search is "copper biocide boiler," and I am sure there are other keywords that would produce results of interest. Copper in marine systems is a different animal from copper in fresh water systems.

I wouldn't say copper in marine systems is all that different since the great lakes fresh water and copper systems are used to prevent biological growth there also. Typical uses are copper based hull coatings, biocides for ballast tanks, etc. The ion generator you linked to is basically the same thing I used for years albeit on the salt water side. Incidentily, I had to test boiler chemistry on one ship I was on for copper/nickel concentrations on a weekly basis. They had a problem previously where too much copper leached into the boiler water from the copper based pipe systems (bad water chemistry) and it ended up plating the boiler tubes with copper. They ended having to re-tube the boilers. Note that the system you linked to controls the copper/silver ions to a very low 3ppm.

Mike

 

[tom in maine]

We have used steel heat exchangers and cast iron pumps in open tank systems. The corrosion inhibitor we had used worked well.
We treating piping, so there was no air space.
The air/water interface has always concerned me when it comes to corrosion, treated water or not.

I guess the good news is that everyone knows more about it now and will be a little more stringent on their water testing.

 

[Como]

So to summarise:

It can happen to anyone.

It is unusual

Closed or open systems are both at risk. (There was mention of British semi open systems, I know it can happen in those)

Boiler make, type etc has a influence on the consequences but not whether it will happen, likewise operation style may make things worse.

Water chemistry is key.

 

[Flathill]

I didn't know that you could enter the water side of a Garn Boiler. Just a safety concern. The inside of a boiler, water side or gas side is most likely a confined space which requires taking serious safety related procedures before entry and during entry in this space. Lack of oxygen is just one concern. Proper forced ventilation is necessary. Also a plan and the required equipment needed to quickly get out of the space should be addressed.

 

[Singed Eyebrows]

It also seems to me, given the fair number of Garn users on this site who have "boasted" (not to disparage the users, because the boasting is out of pride in their belief that they have a superior product) that they regularly run their Garn's in excess of 190 and into the low 200's, that Garn's failure to post notice on this site of the risk of this behavior to the integrity of the Garn boiler is further demonstration of Garn's intentional hiding of a serious risk.

Boy Jim,
For someone who goes out of there way to state "not to disparage the users", you are doing a pretty darn good job of bashing users, manufacture, and all involved. And you are doing it here on this forum, where for the most part everyone goes out of their way to be helpful, and "Non Bashing". I thought Rick didn't want this to degenerate into a bashing thread. But alas........ You must really have been mistreated by GARN/Dectra when you were a child. I for one, am not into boasting, or posting my degree day efficient use of wood btus. I am simply glad to have an alternative source to heating my home over the traditional check to the oil minister. It just so happens, my alternative is a GARN. Could have been a TARM, EKO, ATMOS, or you name it. Most all appliances have their short falls. Last I checked, I have yet to find perfection. Let us all know when you find it! I'm sure you will.....

It appears Garn never did spell out the danger of heating over 190 & that is why there are concerned owners on the site now. Garn was either ignorant of this fact or hiding it, your choice, Randy

 

[TCaldwell]

who would have thought that the silly notion of heating our houses with wood , could be this involved, practically making engineers of us all. While some of the challenges you expect, this is not one that gets much attention untill something like this happens. I applaud rick for being forthright and involving us all in something that we should know more about, unpressureized or pressureized corrosion. As my garn sits in my garage empty this winter, waiting for better weather to start a new garn barn, you can be sure I will not skimp on this concern, probably more so now. In jim's defense this is a very serious concern that dectra has allowed themselves a disconnect due to overfiring, I would be safe to say we all have done it and most not realizing what the results could be. Having said this i would not give mine up, only wishing the r/d money spent on a shiny door went to more direct involvement for something this important. you would think there is a better way to handle this corrosion!

 

[Rick Stanley]

Interesting thread. I don't deal with boilers specifically, but do some work with metal corrosion. It strikes me as strange they only required one water sample and was OK to just walk away from in the spring?

As others have posted, you need high pH and low oxygen to keep the system happy and corrosion free. But these factors are always in a state of change. If you happen to have microbes in the system, their growth and byproducts can change the pH/O2 levels. If the initial fill/treatment didn't kill the colony 100% it will be back. Also, having a large exposed water surface area can allow CO2 / O2 absorption from the air - further lowering pH and raising O2. The fill water source will also have some impact. Well or spring water may tend to have more biological content than treated/city water - don't know if that was a factor or not. I also don't know what all factors were examined in the water test, but iron, sulfur, nitrogen, etc in the water are good bacteria food, so if you had notable levels, that could go to creating good breeding soup as well.

Either way, hope you have it resolved. I'd say keep up with the full spectrum of testing at least until things seem to stabilize. The big key with water treatment - if you are not ahead of the curve in keeping things corrosion free, you are behind it.

That's good stuff right there. I would love it if you guys that are experienced in the biology and chemistry of this stuff would keep talking. Maybe you can make me understand it better. HA, good luck with THAT!!
Here's the thing- I put in the standard start-up additives that came with the boiler, followed instructions to the letter. However, I did NOT take a test sample after two weeks like they recommend, I did it after 4 months of burning and I did NOT take the sample from the manway as they recommend, I took it from the piping in the basement 170 ft away. They tested that sample for -total hardness/total dissolved solids-conductivity/ organo phosphonate digest-drop/ PH/ iron........no test for BIO. All came back ok.
Two weeks later I overfired it and about a month after that I shut it down. It sat there all spring and summer and I never lifted the lid. So, 6 months later I send in another sample taken from the piping and looked inside the manway and gave a brief written description of what I saw in the "comment" area of the test paper that otherwise just has name and date,etc on it. The results came back all OK. Same test as before except this time there was a BIO test and IT WAS OK!?!?!! However, they recommended drain + refill with new treatment OR filtration with 5 micron filter based on my comments. So I drained it and sent them the pics and that's when the cleaning started.
When I talked with Mike he said that the bacteria was boiled away and that's why the test showed negative. But he had said before, in the same conversation, that boiling made steam and that steam and bacteria made the corrosion. So, does overfiring make bacteria eat my boiler or does it kill them?
Mike's a genius, so is Martin and I'm not being critical of any of those guys with any of this. But maybe somebody here can dumb down this bacterialogicalness to a Maine farm boys' level

 

[Frozen Canuck]

Excellent thread, sure gets one thinking about the water in the system, something I have to admit a large portion of ignorance on. However it does shed some light on something I have been wondering about; this fall when I was shopping for a nat gas mod/con boiler for the house I met a (new to me) installer of same. He gave me a quote etc, however he was the only one to insist upon using distilled water for the system fill as well as tank or bladder system filled with distilled water for system refill. On these two issues he would not budge. His explanation was that he wanted a stable reference point to begin from when doing system chemical balancing as well as a known chemical composition on the system refill side that could easily be balanced on the refill side given a known volume. I "thought" OK makes sense but to be honest seemed like a lot of over kill & quite frankly have wondered why so much effort upfront was needed ever since we had our discussion. After reading this thread however I am thinking he is much further ahead at preventing any water side issues before they can occur & damage what would be a pricey boiler in my case as well. A big thanks to Rick for detailing this for us to digest & I can sure understand & empathize as in my case (on a farm) I really dont think I could eliminate all the sources of contamination. There are just far too many of them & they are everywhere on a farm, probably the same for most of you on an acreage, even if you are in control of your acres I doubt you are in control of what drifts onto your property from the neighbors place. Wondering if the poison water that was mentioned in this thread may be the best way to go for large volume situations. That would be approx 95% of wood burning boilers esp. everyone using storage. I would also benefit if this were to turn into a water chemistry/biology/physics discussion. However I like Rick will need it to be at a "farm boy" level. I try to keep up, I really do it is just that sometimes...well you (science majors) make my head spin. No offense, hey maybe I have a water side issue in my brain "causing corrosion" of said brain, that would explain why I feel rusty when it comes to the science of these issues.

 

[heaterman]

It also seems to me, given the fair number of Garn users on this site who have "boasted" (not to disparage the users, because the boasting is out of pride in their belief that they have a superior product) that they regularly run their Garn's in excess of 190 and into the low 200's, that Garn's failure to post notice on this site of the risk of this behavior to the integrity of the Garn boiler is further demonstration of Garn's intentional hiding of a serious risk.

Boy Jim,
For someone who goes out of there way to state "not to disparage the users", you are doing a pretty darn good job of bashing users, manufacture, and all involved. And you are doing it here on this forum, where for the most part everyone goes out of their way to be helpful, and "Non Bashing". I thought Rick didn't want this to degenerate into a bashing thread. But alas........ You must really have been mistreated by GARN/Dectra when you were a child. I for one, am not into boasting, or posting my degree day efficient use of wood btus. I am simply glad to have an alternative source to heating my home over the traditional check to the oil minister. It just so happens, my alternative is a GARN. Could have been a TARM, EKO, ATMOS, or you name it. Most all appliances have their short falls. Last I checked, I have yet to find perfection. Let us all know when you find it! I'm sure you will.....

It appears Garn never did spell out the danger of heating over 190 & that is why there are concerned owners on the site now. Garn was either ignorant of this fact or hiding it, your choice, Randy

Where is this 190* stuff coming from? That is not a magic do not exceed number. Various things happen at various temperatures depending on what exactly is in the water.
There's a lot of science involved in this but there are also a lot of "it depends" and "if/then" circumstances. You could have a certain "cocktail" in your water that becomes active based on practically any water temperature a person could choose. In the case of bacteria for example, there are some that are relatively inert so to speak until they are killed by high temperature (usually boiling) and there are some that cause no problem at all once they are dead. Just depends on what you have in combination with the chemistry of the water itself.

I see a lot of people here making judgments and blanket statements about things that are so variable they have to be dealt with on a case by case basis.
Those kind of comments do little if anything to further everyone's knowledge on this topic. So rather than casting stones at Rick or Garn or Mike from Precision chem let's see what we can collectively learn here.

I called Mike to get his take on Rick's problem right from the horses mouth so to speak. He told me that as he recalled the situation (3-4 months ago) he was not 100% sure it was bacteria in the first place. He recommended that the situation be treated as such in regards to the method of dealing with the corrosion to "cover all the bases". He also told me that testing to find out exactly what was in the water in order to obtain some kind of an idea exactly what was in there would involve a lengthy period of time and thousands of $$ worth of tests.

My best advice is to physically take a look at your water through the lid if you have a Garn as well as regular sampling/testing. Or in the case of a boiler you can't actually see inside of, fill a glass jar with some water directly from your boiler (not from the piping) and let it stand for a day to see what settles out. Then along with that get it tested by a reputable lab for at least the basic properties that are known to have caustic effects on your equipment.

In regards to copper vs steel piping, there are a host of issues introduced by mixing noble and ferrous metals together. Dielectric unions can solve some of them but sometimes create more unintended consequences than they alleviate. Personally, I like steel because you have a lot of "anode" available other than the boiler itself. If you have a steel or iron boiler connected to all copper piping you are guaranteeing that anything "happening" in the system will absolutely happen in the boiler.

Thoughts?

 

[bpirger]

As a new 1500 owner, I'm sitting here feeling a bit queezy as well. Like you say Rick, how could the bio test come back negative? And yet the boilng killed them off? Hmmmm.

One question I have.....at what temp does the Garn "overfire" light come on? Or with the new controller, at what point does the warning light come on? Does it at all? I'm still using my old timer..... But it seems to me, if this is such an issue, should the warnign come on at 185? Hmmm....

I don't recall the manual saying not to fire over 190....though I believe it does (and will be reading). But that sure isn't something I walked away with after reading...a few times. Major concerns with bio problems. YES. Major concern with corrison in general, and Dectra's total non-responsibility for corrosion....YES. And their adamant concern with bio corrosion....YES. But no where did I ever get the connection between firing over 190 and bio problem excaberation. Now I'm more curious than ever to go and read....and to pop the mancover and take a very detailed look.

I wish Garn had their website still around....I guess we will have to get an explicit answer from Garn regarding their recommendation on maximum fire temperature.

Rick, I'm truly sorry for your pain....and I'm hoping these problems are in the past.

 

[heaterman]

Copper is known to have biocidal properties. Is there evidence that use of copper plumbing, rather than steel or pex, with a steel boiler reduces the biological attack issue highlighted in this thread?

Interesting observation. In the marine world we use copper-nickel piping/heat exchangers to the nth degree to basically ward off salt water corrorsion. Marine growth abounds in these systems so we typically use some kind of "poison water" sytem. The one I use now is basically a salt generator much like a pool would use but on a much bigger scale. Obviously you can't use that in any ferrous metal system. Previously I had experience with a copper/aluminum anode/cathode setup where the metals would slowly leach into the water to keep it free of marine organisms. Curiostity made me research this issue and I found this link:
http://resources.schoolscience.co.uk/cda/11-14/biology/copch31pg2.html

Quote:

Copper is used for water pipes and central heating systems (tanks and pipes). This is because it doesn't corrode and its ductility makes it easy to shape and install. It also protects against the growth of unwanted, pathogenic bacteria such as legionella, which thrive in stagnant water storage units.

I would emphasize "stagnant".

This poses the question that with the advancing use of pex (or lack of copper pipe) will bacteria become more prevalent in heating systems? I wouldn't think the copper would leach out enough to make much difference though a high volume system with minimal copper pipe would seem to be more likely to have bacteria problems.

On the lighter side Rick, don't feel so bad. I watched a Star Next Generation episode the other day and they picked up a space bacteria that was eating through their hull. They had to use a neutrino beam to neutralize it. I'm guessing that's not an option.

Legionella bacteria loves water temp in the 90-130* range and will thrive there. The issues that are prevalent with that particular bacteria are running your water heater below 140* and standing or stagnant water such as found in radiant floor systems sold by some less than reputable companies who say it's OK to get your domestic water out of heating system plumbing. A good friend got legionella from the water in his shower (water heater set at the government recommended 120*) and it almost killed him. Legionella does not attack system metals in any way that I am aware of but.........I did NOT sleep in a Holiday Inn last night............just sayin.

 

[brad068]

Amen H-man, Amen.

 

[Kemer]

There is no over-fire light on the new controller

 

[Singed Eyebrows]

It also seems to me, given the fair number of Garn users on this site who have "boasted" (not to disparage the users, because the boasting is out of pride in their belief that they have a superior product) that they regularly run their Garn's in excess of 190 and into the low 200's, that Garn's failure to post notice on this site of the risk of this behavior to the integrity of the Garn boiler is further demonstration of Garn's intentional hiding of a serious risk.

Boy Jim,
For someone who goes out of there way to state "not to disparage the users", you are doing a pretty darn good job of bashing users, manufacture, and all involved. And you are doing it here on this forum, where for the most part everyone goes out of their way to be helpful, and "Non Bashing". I thought Rick didn't want this to degenerate into a bashing thread. But alas........ You must really have been mistreated by GARN/Dectra when you were a child. I for one, am not into boasting, or posting my degree day efficient use of wood btus. I am simply glad to have an alternative source to heating my home over the traditional check to the oil minister. It just so happens, my alternative is a GARN. Could have been a TARM, EKO, ATMOS, or you name it. Most all appliances have their short falls. Last I checked, I have yet to find perfection. Let us all know when you find it! I'm sure you will.....

It appears Garn never did spell out the danger of heating over 190 & that is why there are concerned owners on the site now. Garn was either ignorant of this fact or hiding it, your choice, Randy

Where is this 190* stuff coming from? That is not a magic do not exceed number. Various things happen at various temperatures depending on what exactly is in the water.
There's a lot of science involved in this but there are also a lot of "it depends" and "if/then" circumstances. You could have a certain "cocktail" in your water that becomes active based on practically any water temperature a person could choose. In the case of bacteria for example, there are some that are relatively inert so to speak until they are killed by high temperature (usually boiling) and there are some that cause no problem at all once they are dead. Just depends on what you have in combination with the chemistry of the water itself.

I see a lot of people here making judgments and blanket statements about things that are so variable they have to be dealt with on a case by case basis.
Those kind of comments do little if anything to further everyone's knowledge on this topic. So rather than casting stones at Rick or Garn or Mike from Precision chem let's see what we can collectively learn here.

I called Mike to get his take on Rick's problem right from the horses mouth so to speak. He told me that as he recalled the situation (3-4 months ago) he was not 100% sure it was bacteria in the first place. He recommended that the situation be treated as such in regards to the method of dealing with the corrosion to "cover all the bases". He also told me that testing to find out exactly what was in the water in order to obtain some kind of an idea exactly what was in there would involve a lengthy period of time and thousands of $$ worth of tests.

My best advice is to physically take a look at your water through the lid if you have a Garn as well as regular sampling/testing. Or in the case of a boiler you can't actually see inside of, fill a glass jar with some water directly from your boiler (not from the piping) and let it stand for a day to see what settles out. Then along with that get it tested by a reputable lab for at least the basic properties that are known to have caustic effects on your equipment.

In regards to copper vs steel piping, there are a host of issues introduced by mixing noble and ferrous metals together. Dielectric unions can solve some of them but sometimes create more unintended consequences than they alleviate. Personally, I like steel because you have a lot of "anode" available other than the boiler itself. If you have a steel or iron boiler connected to all copper piping you are guaranteeing that anything "happening" in the system will absolutely happen in the boiler.

Thoughts?

I got the 190 from the thread & thought it was accurate. There seemed to be an issue with the steaming/overfiring, again from the thread. You are going a long ways towards clearing this up Heaterman, Randy

 

[brad068]

At work we produce a class A dry sludge out of a municipal sewage plant. We heat the sludge to at least 158*F for at least .5 hrs. and mix in high cal lime. The heat destroys all bacteria and the lime will neutralize any that made it through and any added during storage ( bird crap, blown in rainwater/snow, etc.), up to six months.

The pH is so high the flys don't even like it or hang around. Flies and bacteria go hand in hand.


Rick,

Was there any chance of air or fices contamination? Do you live on a farm? Is your cover on good? nothing could of got in there during the off season?

Wonder if a mouse would climb up the over flow tube during off season?

 

[nt30410]

I don't recall seeing in my manual (5 years ago) that the boiler should not be fired over 190F...however I vaguely recall a reference made to not add wood if the water temperature was 180F or more. Does this sound right?

 

[jebatty]

I don't have a Garn manual, and Rick says a number of posts above:

He [Chris] and Martin and Mike were all in the loop and when Martin heard that it was Mike’s position that overfiring was the issue, he simply said that it says in the manual to not operate above 190. I guess it probably does, somewhere.

 

[Willman]

So its all about the water quality. Seems logical.The Achilles heel of water heating. What would a testing company look for in the way of contaminants? Most prolly fill their systems with well water. Wonder if city water is better?

Distilled water is prolly the way to go. Knowing the possible metal degradation due to poor quality water would be enough to try to locate a supplier of distilled. Barring that what other purification methods would be acceptable? Reverse osmosis maybe? I am still wondering about full coating of water tanks. Even if a small area started to be affected it would be easy to spot on a yearly visual inspection.

As was mentioned earlier the Garn seems to be easily serviced concerning metal replacement. A plus for this brand versus some others.

Will

 

[Rick Stanley]

I don't have a Garn manual, and Rick says a number of posts above:

He [Chris] and Martin and Mike were all in the loop and when Martin heard that it was Mike’s position that overfiring was the issue, he simply said that it says in the manual to not operate above 190. I guess it probably does, somewhere.

Yup, that's what he said. Not to me directly, but to Chris. But that's the word I got from the manufacturer when I called my dealer.

 

[steam man]

I don't have a Garn manual, and Rick says a number of posts above:

He [Chris] and Martin and Mike were all in the loop and when Martin heard that it was Mike’s position that overfiring was the issue, he simply said that it says in the manual to not operate above 190. I guess it probably does, somewhere.

Yup, that's what he said. Not to me directly, but to Chris. But that's the word I got from the manufacturer when I called my dealer.

I would swear the problem looked to me like the boiler laying idle with an air space in it and chemistry probably off some would have been the cause. I am not familiar with open systems per say so can you tell me what happens at 190 deg to cause this problem?

Mike

 

[Rick Stanley]

[ I called Mike to get his take on Rick’s problem right from the horses mouth so to speak. He told me that as he recalled the situation (3-4 months ago) he was not 100% sure it was bacteria in the first place. He recommended that the situation be treated as such in regards to the method of dealing with the corrosion to “cover all the basesâ€. He also told me that testing to find out exactly what was in the water in order to obtain some kind of an idea exactly what was in there would involve a lengthy period of time and thousands of $$ worth of tests. ]

Yup, that makes sense. Remember, I was freakin' out at the time. I wanted answers and he gave me some. He was taking care of me and I didn't even know it. We had some heated back and forth, for which I have since apologized, and I was about ready for a road trip to MN. He calmed me down and assured me there was a "path to recovery".

Also, Garni, now that you mention it, some of those heated exchanges, mostly me being heated and mike rolling his eyes, were about mice and manure and insects. Mike told of a commune type place somewhere that has a garn in an outbuilding. They are real hardcore minimalists apparently, because they saved their own feces in 5 gal pails over the winter and let it freeze up for use as compost in the summer. ha ha i ain't $hitin ya. When spring came they put all the buckets in the garn barn to thaw them. Somehow it made a fine dust all over everything, BINGO, corrosion in the garn. Yes, this is a farm. Been a poultry farm for 100 years. Manure and dust everywhere. Also, I did the install myself and it took nearly a year. So there was time for something to crawl in a pipe out there or something. Whatever it is/was it's probably cured. We'll find out when I shut down in a few weeks (running low on wood).

Thanks to everyone for trying real hard NOT to make this a bashing thread. I knew it would be difficult, that's why I was reluctant to even post.

 

[pybyr]

As I am thinking about all this, I am wondering- given the fact that the Garn design can't be filled to the brim-- due to the need for expansion area- and the fact that you then have a zone of hot incredibly moist air above the water, it'd be extraordinary if some corrosion of exposed steel did not occur.

I think the questions need to be: "how much is normal?" and "when does it negatively affect function or longevity?"

Some of that may come down to metallurgy- some alloys can experience substantial surface corrosion but will be surprisingly resistant to rust-through.

I suppose if one wanted to get really pro-active about it, you could try to do a slow feed of some inert gas into the top of the Garn- to keep the "air space" as low on oxygen content as possible. Not sure how you'd do that on a homeowner-affordable scale, though-- although, who knows, maybe someone here in the Boiler Room will come up with a way!