Replies

1. 
   calvin | Dec 24, 2002 03:40pm | #1

   Have you looked up or down that chimney?  When was the last time it was cleaned?  You could have a blockage that is screwing with the draw.  The smell might worry me that the chimney has alot of creosote on the walls.  I take it there's no rain cap or screen on top?  As an aside, I have been in a couple houses that have had the same problem.  One in particular needed the chimney top raised a couple of feet to counter the small dormers (height) that were an original upgrade to the house.  That chimney never worked for 50 years until they raised the top.  Best of luck.

   __________________________________________

   Remodeling Contractor just outside the Glass City.

   http://www.quittintime.com/

1. 
   MrMink | Dec 24, 2002 04:02pm | #2

   Calvin, thanks for the quick thoughts on this problem.  I should have included that there are rain caps and a new cement cap was built about three years ago.  The chimmney has been cleaned with only two fires since the cleaning.  If there is a new blockage, will this cause smoke to go down into the lower level?  MrM

1. 
   rjw | Dec 24, 2002 04:33pm | #3

   First and most important, remember, where there is smoke there is carbon monoxide.  Do NOT use that fireplace until it is fixed!  (Even a cheery little Xmas fire could turn deadly!)

   I think you should (i) have the chimney video scoped and (ii) have your house checked by a weatherization expert.  (See the Affordable Comfort site, http://www.affordablecomfort.org/home1.html, or the Building Performance Institute, http://www.bpi.org/ - BPI uses the term auditor.  If you can't find one of those folks nearby, look for a good home inspector.  Where are you located?)

   There are two things going on, I think.  First, there is a gap or hole or void of some kind allowing smoke and combustion products to escape from the flue into the space outside of the flue and inside the chimney.  Even if it's a masonry chimney, there should be a gap outside the flue liner to allow for expansion and contraction.

   Second, there is sufficient negative pressure in the basement to pull that smoke and flue gases back down the chimney into the lower level.

   The lowest level of houses usually (always?) has a negative pressure, but it should be so negative as to counteract the natural buoyancy of heated combustion gases. 

   This is where the weatherization person comes in.  There are several possible causes of excessive negative pressure.  For example, it sounds like you have an electric furnace since you mentioned a cold air return.  There may be significant gaps in the returns in the lower section which are causing the excessive negative pressure.

   Even without the smoke problem, I'll bet a weatherization evaluation will pay for itself in heating cost savings.

   Ash smell?  I'm guessing you have a masonry chimney.  Brick is not water tight (and is actually quite porous,) so water is getting inside the chimney through the brick, getting to where there are smoke deposits and creosote, and then evaporating into the house.

   ________________________________________________

   "I may have said the same thing before... But my explanation, I am sure, will always be different."  Oscar Wilde

1. 
   MrMink | Dec 24, 2002 04:42pm | #4

   Great advice, thanks.