Expert: Bart Ogden - 1/17/2006

Question
This is a rather complex question, so let me start with some background.  I own a 70 year-old home in a Cleveland suburb with a two-flue exterior chimney.  One flue goes to the first floor fireplace (used) and the other goes to the basement (not used).  When we're not using the fireplace, the house is filled with a smoky smell that I can trace back to the first-floor fireplace.  We hired a contractor to place a top-sealing damper on the chimney with the assurance that this would help, since the smell should be carried by a downdraft.  Now that the damper is installed, the smoky smell is as bad as ever.  In addition, whenever we use the fireplace on the first floor, the basement now fills with smoke!

So, I have 2 problems.  First, the smoky smell when not using the fireplace.  Could there be another reason for the smell entering the house?  We had the chimney inspected and the chimney sweep said the flue is in good shape.  He suggested that the furnace may be creating a negative pressure in the house, pulling air down the chimney...Do you have any suggestions about what to do about this?

Second, the smoke-filled basement when we use the fireplace.  Our theory is that the top-sealing damper (which vents smoke to the sides) is directing its exhaust over the flue for the basement fireplace, which is being sucked down into the basement.  Does that sound likely?  What would be the best way to prevent that?  I would have thought a top-sealing damper, but we certainly haven't had much luck with the one we installed.

Thank you very much for any help you can provide,

Ken Cummings  

Answer
Ken,

You're experiencing a pressure problem in the house, probably amplified by stack effect.

Visit www.csia.org to find a local CSIA Certified Chimney Sweep in your area, then make sure to choose one that has experience with pressure testing, diagnosis and troubleshooting.

Thanks for using AllExperts.Com!

Sincerely,
A. Bart Ogden, President
Home Safe Hearth & Chimney
Wichita, KS
www.homesafeks.com