Thirty years ago, I converted from oil heat to natural gas heat, but didn’t line the chimney, as I think I probably should have. So now I’m thinking that I should do so, as I just replaced the furnace again.
The chimney the services the furnace has three flues in it: two fireplaces, plus the combination furnace and water heater (also natural gas). There are separators in the chimney to separate the flues: one brick thick. And the chimney is also only one brick thick.
What do you think the best solution is: stainless steel liner, the pour-in concrete approach with the bell-shaped former, other? And who do you think would be a reliable installer? My fear is that the installer damages the chimney and I have to rebuild it from the basement up! Chimney is about 35′ from the beginning in the basement to the top.
Location: Montclair NJ
Thanks for any help
Bob Chapman
Replies
I think that a stainless liner would be the way to go. It's too bad that you already replaced your furnace. You could have used the chimney reline money towards high efficiency direct venting equipment.
The advantage of the cementitious liners - http://www.supaflu.com/aboutus.htm - for example, is that they strengthen an older chimney. The advantage of stainless is that it is less expensive, quicker and less messy.
One problem with furnaces and water heaters today is that they are so efficient that the exhaust heat (loss) isn't what it used to be - tending to cause a problem with condensation in the chimney itself. This can be significant in that acids can be produced that eat up the chimney, meaning that a S.S. liner might be the best for the B vent (furnace and water heater).
Your mason needs to calculate whether or not the fireplace openings can adequately be served by the size of the (reduced) flue after either SS liner or cement - this goes directly to code requirements and actual draw.
I know a good guy about 1 1/2 hours south of you - let me know if you want his name. I can check with him to see if he'd go to Montclair.
BTW - this is not a cheap undertaking - you know that, right?
Jeff
Thanks, Jeff. Yes, I wold like the name of your person,please.
Bob
I did a stainless liner. It was a piece of cake. I had a single thickness brick chimney that had a 6" galvanized pipe sticking out of it in the basement that was cemented in. I removed the pipe and dropped the liner down from the roof. The cap was already attached to the liner, so I used an adhesive to seal it to the top of the chimney. Then there is a collar that goes into the masonry and is mortared in. The liner comes through the collar and attaches to the flue from the furnace and the water heater via a "y" Once I got all of the loose mortar and dead birds out of the chimney, it was easy. I think it cost me less than $150 for the 35' liner.
Thanks for the info. I hadn't considered that it might be a DIY proposition! I've done everything else on this house, why not a liner!
Bob
You have an unlined chimney and with only one brick thickness on one that old, it is very unsafe in many ways.
IMMEDIATELY discontinue any use of the fireplaces for burning.
The furnace installer should have relined this as part of his install.
reason - the newer more efficient appliances burn less often, so the masonry mass stays cool and acquires a lot of condensation which is hard on the mortar, eating it away from inside. Some of this when you were burning oil was in the form of sulfuric acid.
But since your appliance probably requires a 4" to 6" flue a,d you probably have an 8" to 16" flue, that means a lot of the exhaust lingers and does not draft up and out. With mortar joi9nst eaten away and porous, the toxic exhaust is escaping into your living space. How much? I can't say, but how much is good for you?
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Thanks for all the responses.
We aren't using any of our fireplaces as DW doesn't like the dirt in the house that results from their use, so we are not in danger from that source.
I do want to get the chimney lined for the furnace, before we have an issue with that.
Bob