dark stains on chimney

Ontario, Canada   


I recently bought a home that is around 50 years old. it has a chimney that at one point was use for the purpose of burning wood.

The previous owner changed it and put in a gas fire place. The chimney is still there, but inside the house at the very bottom of the chimney there is some sort of a cap in the side of the Chimney,

There seems to be something dark coming from the bottom part of the cap.

I tried putting silicone around it but the dark liquid still keeps leaking. Do you have any suggestions for this problem?



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by ChimneyChick | September 25, 2015 ChimneyChick's avatar
Midland, Ontario

the dark ‘liquid’ is liquified creosote. It probably is the result of the moist gas emissions going up the chimney that was not swept prior to the gas appliance being added.
My best suggestion is to go to http:www.wettinc.ca and find a WETT Certified Chimney professional in your areas to come and do a full assessment and sweeping of the flue BEFORE any other appliance is installed to this chimney system.

This technician MUST not only ensure all the residue is removed from the system but to also ensure there are no cracked or damaged liners within the system. When you put a new appliance into this chimney,m install a proper stainless steel or [aluminum of gas] into the channel.

by 2020 | October 28, 2015
Santa Fe, New Mexico

This “cap” is very mysterious.  Why would there be a cap in the side of the chimney, especially at the bottom?  It might be a cover for a flue from a previously used heating appliance that shared the chimney, but why it is leaking a “dark liquid”, whether creosote or anything else. This kind of problem really can’t be solved without a site visit by an experienced chimney contractor.

by ChimneyChick | October 29, 2015 ChimneyChick's avatar
Midland, Ontario

The “CAP” at the bottom side of the chimney is probably the old clean out door, If you have black coming out then the chimney was probably not swept prior to the installation and if the new gas unit was not lined it is the mix of gas condensation and old soot running down and out. find a Certified Professinal at http://www.csia.org

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