Guys, if the 190* temp is critical, why not use an aquastat to kill the fan when the water hits 190* even if the unit still has wood left?
Thanks to everyone for trying real hard NOT to make this a bashing thread
That might turn a clean burning Garn into a "smoker". I hope that the water treatment gurus can come up with something bulletproof, RandyHydronics said:Guys, if the 190* temp is critical, why not use an aquastat to kill the fan when the water hits 190* even if the unit still has wood left?
Hydronics said:Guys, if the 190* temp is critical, why not use an aquastat to kill the fan when the water hits 190* even if the unit still has wood left?
bpirger:The Garn manual says 9% of units are affected by corrosion…and most of these have been bacteriological in nature.
heaterman said:Hydronics said:Guys, if the 190* temp is critical, why not use an aquastat to kill the fan when the water hits 190* even if the unit still has wood left?
That is totally contrary to the design and operating characteristics of a Garn. Once the wood load is going it never shuts down. No cycling = clean burn= very good efficiency=lower wood consumption.
People would start using it like any other boiler. By that I mean loading it full and just letting the aquastat cycle the air flow much like an OWB. Due to the nature and design of the heat exchanger tubes in a Garn, idling is something to be avoided at all cost.
My advice to people who are running a Garn is simply to avoid firing the thing unless water temp is below 170*. The top temp will finish around 190-200 unless a person has severely over loaded the unit.
Rick Stanley said:I have wanted to to share this since it happened last November. I want this NOT to be a Garn bashing session although I was VERY pi$$ed when it happened. So I have waited, cooled off and checked things out so as to figure out and share WHY it happened and what we did about it, so others (including Dectra, Garn dealers and PrecisionChem) could benefit and save themselves some hassle. After all, education and sharing is what the Boiler Room is all about.
So, I got the Garn online in Oct of 09. Followed all recommended start-up/flush/add chemicals/fill/water-testing (done in Jan/10) procedure. Water test (chemical analysis only, no bio test) results were ok so ran it all Winter, shut it down in the Spring, walked away and let it sit idle all summer. In the Fall, last November, in between getting wood put in and other getting-ready-for-winter farm stuff I drew a water sample from a purge valve near the heat-exchanger in my basement and got it sent of to PrecisionChem. There is a spot on the bottom of the water test form for remarks and comments. I had put in there what I could see through the manway and that was that the water was clear enough to see the flue tubes but had a brown color and that I could see brown foam floating at the water line against the tank wall. The results, including a bio test this time, came back A-OK!! But, because of the comments, they recommended draining, flushing and re-filling with new treatment.
When it was drained it looked bad so I snapped these pics and emailed them to Mike at PrecisionChem. He responded right away, set-up a time to call me, we discussed a plan of attack or "path to recovery"as he put it. He said the pics showed for sure that there was bacteria in the water and excessive steam production at the waterline had created an environment that caused corrosion.
Willman said: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
bpirger said: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.
bigburner said:Deionized was recommended. ------------- better check that, it may not be hard on steel but it will attack copper in a big way from what I can remember.
bigburner said:Deionized was recommended. ------------- better check that, it may not be hard on steel but it will attack copper in a big way from what I can remember.
Der Fiur Meister said:Willman said: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
We used city water. Mike tested our tap water and found bacteria. Didn't ask what flavor.....
I've been told not to use distilled or RO water. Deionized was recommended. No local source and you still need to test and treat regularly no matter what water you use.
Like Rick I was really upset. The only real answer I've heard is test / treat / monitor.....test / treat / monitor.....test / treat / monitor.
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