Chimney Liner for High-Efficiency Oil Boiler
So the previous owner of our house installed a new boiler with a (relatively) high efficiency (86.9% AFUE). The flue was run to the old brick chimney (all brick, no clay or other liner), but no SS liner was installed As to be expected, the chimney has been starting to degrade and some fairly gross water has been dripping down the outside of the chimney inside the house.
Obviously I need to run a stainless steel liner from the existing flue in the basement to the top of the chimney and install a cap / rain guard. I’m planning on doing this myself to save costs.
After discussions with multiple experts, I have come across mixed advice concerning material choice / cost, which I am hoping to clarify here. One supply house has told me that 316ti material will not hold up to the condensation from the high efficiency boiler and that I need to use an AL29 liner, which is double the cost ($1400 vs $700). Another installer said 316ti has decent corrosion resistance and will still last quite a while, even with the high efficiency boiler.
We are going to be selling the house soon so I really don’t want to spend tons of money here, but I also refuse to do something completely wrong just because it won’t be our problem in the near future.
So my question is whether the AL29 liner really worth double the cost of the 316ti, or is this just a supply house pushing for a higher priced option?
Thanks
Isaiah
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Replies
Did you really read what you wrote?
Imagine you are on the jury and they make some guy read your post and answer this question
“So Mr. Smith you knew the liner you installed was inferior and would fail in time and could kill everyone in the house?”
Is there a water heater sharing this chimney?
I know the pros don’t work cheap but do you want to bet people’s lives on your DIY skills?
Walta
I feel like that's a bit harsh given I explicitly stated that a) I won't do something wrong just to save a buck and b) I've gotten conflicting advice from two different experts on what is acceptable. I'm perfectly capable of installing a liner myself, I am simply trying to verify whether one product is worth twice the price of the other. I'd rather learn everything I can about the products, codes, installation process etc. and be able to make educated decisions than simply trust an installer (plenty of professionals give bad advice).
Like I said, one installer told me 316ti would be fine. I could take him at his word, but instead I am researching further to understand it better. If I were simply going the cheapest route, I would have accepted his advice and gone with 316ti, but I'm not. I come here for expert advice and not to be criticized for asking questions.
As far as the setup goes, the boiler does both hydronic heating and water heating through an indirect tank, so the boiler flue is the only thing connected to this chimney
I had a similar problem some years ago with my unlined brick chimney. After trying various ways to stop what I thought was a leak from outside I found the the real cause. Rodents had filled the air space between the bricks and the interior wall with nesting stuff. This material was wicking moisture from the bricks and wetting the drywall.
The guys over at heatinghelp.com had a couple of discussions on the subject. The takeaway seems to be that 316ti is good for higher flue temperatures (900-2100 degrees) common with wood and pellet combustion and also good against sulfur corrosion which is a significant risk with oil boilers. AL24 is the new kid on the block which is part of why it is so expensive. It is good for lower temperature combustion accompanied by chloride corrosion that is common in seacoast areas and to some degree in threshold-condensing gas combustion equipment. It sounds like the 316ti would actually be more appropriate unless you have a high-corrosion environment for some reason.
Thanks Peter, that seems reasonable and consistent with the other pieces of feedback I've gotten. I have yet to hear anyone indicate that the 316ti would be dangerous, which is easing my mind a bit. I tracked down the installer who put the boiler in and gave him a call today, and he said he just puts in the standard 316ti and doesn't worry about it.