Wood stove/double flu chimney

QuestionEdit

We burn wood in a Vermont Castings Encore stove in our living room. It heats very well. However, we have an outside double flu 25' chimney (one side for the wood and the other for the oil furnace). On quiet, warmer days smoke from the wood fire comes back down the oil furnace flu. It smells up the entire basement. When the oil furnace is running and that flu warms up, the problem seems to go away, but that kind of defeats the purpose of the wood stove since it means burning more oil. Someone suggested cracking a window in the basement just enough to equalize the air pressure. This does not seem to work. We were also told to build a weir between the 2 flues on the top of the chimney, which we did to no avail. Another suggestion is to extend the oil furnace flu by adding a length of pipe to the chimney on the outside. We haven't tried this yet, but wonder if you think this would work. Another suggestion, is adding an air induction kit to the wood stove, which allows fresh air from the outside into the wood stove (not sure why this would help in any way for the oil chimney).On colder days, we have no problem. The stove works great - it's the chimney that is giving us the problem.

AnswerEdit

There are many other reasons a fireplace/wood stove will smoke, negative pressure, that is hot air rising in your home (and getting out through the attic vents, doors, lights) your house is a better chimney than your chimney. Also kitchen/bathroom exhaust fans, Radon systems, cloths dryers and the furnace all take house air out of the house (mechanical negative pressure) I would have a local Certified Chimney Sweep www.csia.org, (there you can look up by zip code to find one near you) take a first hand look at what you have they should be able to help.