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My SIL was helping me clean and when I got out there he had these.
It looks like rust but could be scale? I thought my boiler was stainless. I'm not sure if I want to ask the manufacturer yet. I'm afraid they will say creosote did it or I did something I should have known better.
Looks like metal, but it must be scale. If it were fire tube, the firebox would be full of water. That's assuming the Elite II 200 is a boiler. If it's a furnace, the house would be full of smoke.
Like maple1, I'm confused about the term "flu." That's typically a description of a chimney. But the diameter is way too small for a chimney.
I suppose it's possible that it's part of a firetube that hasn't been completely corroded out. But I doubt it.
That looks just like what I got out of my stove pipe tee this past summer. I had to replace it as I could see pin holes through it. It was only 3 years old. Boiler tube should be a lot thicker than stove pipe, but that's still not good
First you need to find out if it's metal, appears to look like scale from the inside of the tube. I used their rotary tool when I had my elite 100 so the crude coming out of the tubes was not cylindrical shaped like the tube.
It is slightly magnetic, barely hold itself up with strong magnet.
Yes return water no less than 140.
It is from the flue tubes not chimney.
Chimney has cap.
If it's slightly magnetic it's iron oxide (rust). Now to figure out why oxidation is occurring in the tubes. It's a high heat area and rust is usually killed by heat. My first thought is bad steel.
I can sort of understand not wanting to open the possibility of incoming criticism or opening cans of worms - but I think I would show this to the dealer & manufacturer & ask them what the heck is going on. I can't imagine what kind of operating conditions/procedures would lead to the tubes making rust like that - short of the fire being out for days at a time at the same time rain water was coming in the top, or something of the like. Do you ever have any condensation showing anywhere near &/or inside the HX?
Ya, I wasn't sure about the construction & access on it - was also wondering if there was just a cover on top or bottom you could pop off & take pics from there.
Manufacturer said it is minor and happens during the summer when the boiler is cooler than air and forms condensation that forms rust. He said best remedy would be to swab out the tubes with a oily rag after spring cleaning. Sounds reasonable. I do use it for heating the pool every couple weeks but I will just have to do it again. I have gallons of hydraulic oil from the tractor.
I do not wish to be negative on this but I would question the manufacturer's claim. That's a huge cross section of rust to be caused by summer condensation. I would expect a very thin layer from condensation but that thickness would have me concerned. Rust (oxidation) is natures "anodizing" which forms to protect the metal. That thin layer of rust would protect the substrate from continued oxidation by shielding it from the air. It would take several years to produce that thickness of rust under normal conditions with quality steel.
I second Fred's concerns, and would only add that it seems odd to me that your boiler does this, but mine, which also has fire tubes and sits idle all summer, doesn't. In addition, based on your photo, the volume of corrosion seems to be limited to one tube, suggesting to me a material or manufacturing defect. If a tube or tubes rot out, I doubt there's any way to repair it.
Think I agree. There are all kinds of boilers on here with tubes that sit idle & 'cold' all summer (not really 'cold', but at room temp), and this is the first thing like this I've read about. I think the only possible way to make that happen, was if really cold water was running through it constantly, and it was sitting in very hot & humid conditions. Otherwise, the boiler temp would equalize with the ambient air temp, more or less - sometimes might be a bit less, sometimes might be a bit more. Even if there were no reports of rust scale per se, there should be some of condensation running/dripping and collecting somewhere, like a secondary chamber - haven't read of that either.
From my experience If any wood or pellet boiler is left over summer without cleaning it out thoroughly ash because of it's high acidity can corrode metal when it comes in contact with moisture. Is this an indoor or outdoor boiler?
I can not ascertain for sure, but by looking at the boiler model posted above, the heat exchange tubes, seem to be directly below the collar/flue. Also do not see any info regarding the type of chimney/offsets, etc.
I can not be sure, but it looks like some of these pieces may have pits and tubercles, which is a positive sign for dissolved oxygen based or moisture oxidation. If the flue/chimney is condensing heavily and running down into the HX section, this may be the causality of 2 events, creating the rust.
Of course accumulated ash, left deposited with added moisture would also cause fouling, but I am not sure it will be of this type, or magnitude, especially after such a short operational life span..??not sure on the life of the unit.
Finally, as Fred mentioned above, another factor would be metal fatigue...caused by the aggravation of constant thermal cycling of bad metal ....
Scott