fireplace smoke

[grumman41]

I have an upstairs and downstairs fireplace, there are two chimneys about 20" apart. The problem I have is when I build a fire in my upstairs fireplace the smoke settles into the agacent flue and makes my basement smokey. I have have capped the second flue to stop the problem but would like to use both fireplaces....any suggestions?

Thanks in advance!

 

[LLigetfa]

Extending your upstairs flue would be the easiest solution. Balancing the air in the home to eliminate the negative pressure causing the flue reversal is the ideal albeit somewhat harder solution.

 

[cmonSTART]

Try cracking a window or door downstairs when this starts to happen. See if the smoke stops coming down the flue. If it does a passive air inlet may be in order.