Smoke problem in basement

[tom]

I'm having problems with smokey smell in our basement near the fireplace when we have a fire in the upstairs fireplace. We have a double sided fireplace in our living room and a single sided directly below it in the basement. The chimney has three flues; one for up, one for down and one for the boiler, all three side by side. We don't use the boiler chimney anymore since we have power vent. Not sure if it is a problem of positive/negative pressures pulling smoke in from the top of the chimeys all the way to the basement or if it is a leak in the mortar joints or something like that. We keep the fireplace doors open when we have a fire upstairs. No chimney caps on top, so maybe I should start there? Not sure who I would get to look at either. Seems technical and maybe not for your average chimney guy. Thanks.

Also, looking to put a coal stove in downstairs to assist with heating bills. Should a coal stove typically smell? Wife is concerned.

 

[begreen]

Are the two flues next to each other and at the same height on top?

http://www.extendaflue.com/products/extend/extend-a-cap.html

 

[tom]

Are the two flues next to each other and at the same height on top?

Yes, All three are same height. I suppose I should at least cap or fill the former boiler flue.

 

[begreen]

This could be a combination of low basement pressure and the identical height flues. Extending the upstairs flue will help. Take a look at the extendaflue boost cap.

 

[tom]

Thank you for the prompt response. I'll check it out.

 

[Backwoods Savage]

I agree with begreen on this. Same height can really cause problems.

 

[missedbass]

I would cap the flue. I think you are pulling air in from the flue not being used. Also make sure you have a source of make up air

 

[dmmoss51]

crack a window and see if it helps... probably negative pressure in the house pulling air down that other chimney...

 

[missedbass]

crack a window and see if it helps... probably negative pressure in the house pulling air down that other chimney...

yep. That should do it. I have replaced a few spill switches on my boiler due negative pressure

 

[HotCoals]

A upstairs window open can actually cause it by pulling on the intake air.