Expert: Paul Karthaeuser - 12/1/2011

Question
i have a 3 sided masonry fireplace with metal chain around it. I cant use it. when the fire is high there is no problem but when it goes down the house fills up with smoke. please help me figure it out. i tried a few things had flew all the way open and half way open still same problem. flew is clean, chimney opening is around 43 inch length and 21 inch width with flew pipe around 15 inch opening. and the chimney outside is about the same height as the highest point of the house. its a ranch house. please tell me what to do so i can use it. thanks

Answer
Please forgive the delayed response as I was away this past week and did not change my setting to alert people of this fact.
When you say you have a three sided masonry fireplace you mean that three sides of the firebox are open, correct?  If that is the case then you are fighting an up hill battle from the standpoint that you have a very short chimney on a ranch house just because of the home and chimneys height.  Then you are also fighting the huge volume of air that this fireplace is drawing in for combustion and utilizing to fuel the fire, hence sending all of this air and smoke up the chimney.  If the dimension of the flue inside diameter is correct that you gave me then the flue is of adequate size however you will not have very good draft in this situation with a ranch house and very short chimney system.  There are other factors that can be affecting the draft and operation of this fireplace in a negative way such as the design of the house and how tight the construction.  In other words if you have newer windows and doors that seal really well creating a very "tight" home you will have fireplace venting problems and may need to bring in additional make up air to the home.  I would suggest testing this idea by opening the door or a window opposite the fireplace next time you use the fireplace and see if allowing for additional air to the home helps this situation.  If it does then you know what the problem is and how it needs to be fixed.  This is the most I can offer you in terms of advice given the information I have.  I hope this has helped you.  Please take a moment and rate my response to you on this website. Thank you.

Paul