Garn anode rod service bulletin

I think the anode service bulletin was sent to people who have signed up for the garn news emails, hopefully anybody who bought the bad rods should be contacted. In dectra's defense they seem to be conservative to change, researching and testing before putting to market, in the end I would have to believe the fix will be good.

I agree Tom. Good company, built good boilers for years. I read about this in the bulletin, sent them an email which was answered within 12 hours. Later this week I'm going to try to use my trusty 40 year old Sears portable electric pump, and suck the goo from the bottom of the tank without stirring too much up. Will report how it goes here.

In 2009 when I moved my Tarm w/1000 gal storage tank to my new shop, I used Mike's boiler water treatment for my system when I refilled the system. My system is a pressurized-closed system, and I have added very little new water since, mostly to replace very small losses when I have done some plumbing maintenance, and I have never had it retested.

Looking at your statement regarding nitrate, I needed to refresh my memory as to why this is important. A quick search found that nitrite acts as an oxygen inhibitor (not a scavenger):

"The major problem in low-pressure heating systems is corrosion caused by dissolved oxygen and low pH. These systems are usually treated with an inhibitor (such as molybdate or nitrite) or with an oxygen scavenger (such as sodium sulfite), along with a synthetic polymer for deposit control. Sufficient treatment must be fed to water added to make up for system losses, which usually occur as a result of circulating pump leakage. Generally, 200-400 ppm P-alkalinity is maintained in the water for effective control of pH. Inhibitor requirements vary depending on the system."
http://www.gewater.com/handbook/boiler_water_systems/ch_11_preboiler.jsp

... and this from Mike's website:

"Nitrite Test Kit - The best in accuracy, this kit includes everything to perform +/- 10 tests with complete instructions. Regularly checking your system assures that your system is properly treated. This method directly tests chemical level. This is the testing method that we recommend for maintaining your system with the proper level of Treatment Solution 101, 500-1000ppm of Nitrite. 500-750ppm is adequate for most fill waters while a residual of 750-1500 gives maximum protection."
http://www.woodboilersolutions.com/testing_solutions.cfm

Because the Garn is an open system, it seems that maintaining an appropriate level of oxygen inhibitor is important. I assume that the anode rod problem is unrelated to the oxygen inhibitor level.

There must be lots of air mixing with the water in the Garn to require frequent nitrite treatment. I'm wondering whether a separate open expansion tank, with a small vent, and then filling the Garn to the top, would help in limiting the water mixing with air. Open expansion tanks have been commonly discussed in this forum, and were common in old water boiler systems (the expansion tank in the attic).

Since 2010 when I installed, I only have added one pail of chemicals to my Garn...once....after the 4th year. I have topped off the tank level (filtered garden hose) three times I think....have not yet done a complete drain or perform and plumbing mods requiring losing much water. I know the first year or two I didn't have a tight man hole seal like I wanted....so I fixed that by replacing the gasket and assuring a nice tight fit. Big difference in water loss. Once you remove the cover, seems that the gasket needs to be replaced....certainly after 4 openings in a 2 year period (my experience). I wonder what the difference is Robert in your system. Was you initially water sample test noteworthy at all from Mike? Do you replace lots of water?

I bought numerous rods from Dectra...I did receive the bulletin from them (I am also signed up for the e-letter)....did receive anything that said "as a Mg rod buyer...."

bpirger said:

Since 2010 when I installed, I only have added one pail of chemicals to my Garn...once....after the 4th year. I have topped off the tank level (filtered garden hose) three times I think....have not yet done a complete drain or perform and plumbing mods requiring losing much water. I know the first year or two I didn't have a tight man hole seal like I wanted....so I fixed that by replacing the gasket and assuring a nice tight fit. Big difference in water loss. Once you remove the cover, seems that the gasket needs to be replaced....certainly after 4 openings in a 2 year period (my experience). I wonder what the difference is Robert in your system. Was you initially water sample test noteworthy at all from Mike? Do you replace lots of water?

I bought numerous rods from Dectra...I did receive the bulletin from them (I am also signed up for the e-letter)....did receive anything that said "as a Mg rod buyer...."

Click to expand...

I bought my garn used but very close to new. I did have a problem with the cover sealing. Like bpirger I put a new seal on it and have been afraid to open it since. I do have a filter in the garn loop and always seem to have a heavy white slime on it. I have added some water but I would not say it is excessive. My water is super clear and smells normal. I can't say for sure that I have treated the water since I sealed the cover. My initial fill test was good. I will probably have to add the powder through the anode rod hole. I will add the treatment again and give it another year. Overall the thing is great and fits our needs well.

My 1st attempt at sucking the rod stuff off the bottom of the tank had mixed results. The 1st hose I tried to use was too soft for sucking 125 degree water, as it went flat in no time. I found an older harder one. and it worked better. I got some chunks 3 or 4 inches long, they'd stick right on the end [i had the hose taped to a 6 ft pole] I'd have to pull it up 'till the end was almost out of the water, pick the part off & go back down. By the time I got 25 to 30 gallons of water into a 55 gal drum, the water in the Garn was too cloudy to see through. I'm sure I'll be doing the Y strainer in a day or two. Once the tank settles, i'll be able to see down in it, how much I missed, etc. Had to add water when I was done.

Well I drained the WHS2000 over the weekend and got the tank squeaky clean by using a power sprayer for several hours and then crawling into the tank for a few hours and scooping all the debris out that would not spray out the front drain hole. (Wish the design of that drain was lower as this would have helped a lot.) Then spent a few more hours with a water hose spraying the fine silt out the front drain.

For those of you trying to decide whether to drain/clean/refill, here is what was still on the tanks bottom after draining and 2 hours of power spraying:



This debris equals about 1/2 gallon by volume. I can't imagine that I would have been able to remove more than a fraction of this without draining and crawling in.

I see the final installment of the anode rod issue from Dectra (release 3) states to set things up as a single point or isolated ground and just forget about the rod altogether.

To me, I'd think most installations would be the one were everything is tied to the same panel....out in the Garn barn, one supply line would feed everything there. The key thing here is not have a separate ground rod installed to the Garn in the garn barn. I know I had the rod, then disconnected the rod to see if it made a difference in rod consumption, and found it made no difference. So everything is tied to a single panel connection.

So, according to Dectra then, I have no electrolysis issue...and all my concerns have been because of excessive rod consumption, and not real electrolysis issues.

I've never been able to measure a potential difference from the garn to the grounding in the garn barn (any of the plumbing, blower motor, pumps, etc.)....and didn't understand what could be introducing my problem.

And perhaps now the statement is there is no problem? Hmmm. Maybe there is too much concern about nothing from the get go?

I have all that crap on the bottom of my tank as well. Maybe I'll let it cool off and jump in with a big snorkel and clean it out. LOL Please don't try this at home.

There apparently are Garn units out there that have been running for over 30 years. Do those units use anode rods? If I spend a huge amount of money to set up a Garn system is my unit going to last 30 years without the anode rod protection?

I guess an equivalent amount of money would get me a luxury SUV which will only last for five years. *grin* Maybe my expectations are too high!

heres a small bit of knowledge I have about anodes, not sure if it applies to boilers, but here it is. I was a power co. lineman for 35 years before retiring. In the early 70's, subdivisions around here were really booming, and it was decided underground looked better than poles - The first few we used what we called submersible transformers, they went into a concrete vault some 6 ft deep, under each vault we dropped an anode ring, and bonded it to our neutrals. Most of these vaults had 7 to 13 thousand volts primary coming in, and 120/240 going out. If there ever was a place for "stray voltage" it'd be in there. Some of these are still in use today, i know of none that failed because the tanks rusted or failed. Some failed due to lightning, we replaced them with the padmount [green box] type when we could. We never went back & tested the bond to the anode, nor replaced it [being under the vault] The main reason we went away from the submersible was no live switching could be done, you had to kill the whole area to do something in a vault. Is it really needed in a boiler? Time will tell I guess, Some cars today don't even have dipsticks I hear -

My stray voltage fix it kit came in the mail today - 5 neoprene washers to isolate the blower motor from the tank. You do need a 5/8" drill bit to enlarge the holes in the motor plate to fit the washers. I have a few 5/8's drills. I'm sure some won't.

Does the control panel also need to be isolated?

Nothing about that in the directions that came.

During the seventies and eighties I spent my time servicing electric boilers in southern Ontario. These were used to heat domestic hot water for apartments and hotels. Most of these started out with a glass coating AND an anode. The tanks were about 3/8 steel and had a lifespan that varied greatly, always rusting out around the elements where there was hottest water and decreased water flow with calcium build up.
Since it was domestic water we could not add any chemicals, but during the last years we were testing an "electrostatic water treatment". This consisted of passing the water thru a large capacitor and while I started out thinking "snake oil", after 5-6 years my opinion changed 180 deg. Now that I am back working with a boiler I cannot find any trace of the company.

Regarding too pure water----pure water is a very active solution and will etch glass. I have seen it dissolve copper pipe and elements in months. After it dissolves some metal, it is no longer "pure water", this is the basis behind a sacrificial anode.