have two stove pipes side by side, smoke coming IN one!!!

[rtv900]

as title states in too few words. . . .so I have a wood stove on my main floor and just this year put the 2nd in the basement. Two completely independent 6" double wall pipes. Since I just put the 2nd one in, today was the first time I burned the middle floor one (original stove). At one point I went downstairs and it kind of smelled smokey just a tad, so I went over to the stove and opened it. At first I didn't notice anything but then I opened the damper all the way and I could see smoke coming down into the stove and then out into the room, flowing in. I closed the damper immediately and the visible smoke stopped but I'm now assuming it's still leaking in little by little.
Is this a carbon monoxide issue I should be concerned about?
Is this normal with two side by side pipes? (they're probably 6 feet apart)

I ended up lighting the basement one because I wanted to at least stop any in flow of smoke.
so now they're both burning good and clean so I'm positive nothing is flowing in now, just want to know what I should be thinking or if I'm over thinking it all together.

 

[Woody Stover]

I went over to the stove and opened it. At first I didn't notice anything but then I opened the damper all the way and I could see smoke coming down into the stove and then out into the room, flowing in...Is this normal with two side by side pipes? (they're probably 6 feet apart)...I ended up lighting the basement one because I wanted to at least stop any in flow of smoke.
so now they're both burning good and clean so I'm positive nothing is flowing in now

Some others that are more knowledgeable will hopefully weigh in soon, but my understanding is that the "stack effect" of the house (warm air leaving upstairs) will pull air in below the neutral pressure plane of the house, pulling air down the basement chimney. I think that having the stacks at different heights at the top will help. If you mainly burn the upstairs stove, maybe put another section of chimney on top of that one...I think..??

 

[GreenMountain]

I think your problem is essentially the same as mine:
https://www.hearth.com/talk/threads/getting-stoves-to-coexist-on-two-floors-possible.164400/

Initially, I had stack effect issues - in cold weather, cold air was coming down the downstairs stove's flue, which is in an uninsulated chase. Presumably the house has some leaks higher up, so the warm house is a better flue than the cold triplewall. I think I've fixed that by raising the wall penetration, so that there's 3' of warm singlewall inside the house, and the top of the flue is 3' higher outside. I don't get any passive draft down the flue now, though it hasn't been truly cold yet.

However, that didn't solve the problem when the upstairs stove(s) are burning. It seems that the upper stove's larger size and stronger draft is enough to backdraft the lower stove when it's not running hot.

I think the answer might be an outside air kit for the lower stove, but no one else has weighed in with an opinion yet.

The one thing I can say for sure is that I would not count on different stack heights solving the problem. Whether your basement stove is sucking down smoke or air is immaterial, because it will have plenty of odor and potentially CO from its own pipe and embers in the fire box.

 

[rtv900]

yeah maybe I should get a CO detector in the basement
I feel like this will continue

 

[GreenMountain]

What kind of stove do you have downstairs? An outside air kit might be a pretty easy fix. (In my case, I have an original Intrepid, so that's not an option.)

 

[rtv900]

its a quadrafire 3100 I think
flat steel construction, but the damper works well
I have been thinking of an outside air kit but just not sure
it would be a ton of work drilling through the wall

 

[GreenMountain]

There's always the traditional New England farmer cheat of going through a windowpane.

 

[electrathon]

I think the answer might be an outside air kit for the lower stove,

Absolutely. Your stove is sucking air out of the house, it must come back in from someplace.

yeah maybe I should get a CO detector in the basement
I feel like this will continue

It will. This is between unsafe and life threatening.

 

[rtv900]

it felt the same as any time the stoves aren't running and it's just very cold out.
You know how if you open the damper and open the door you can feel the cold air flowing in? Even when nothing is consuming air, just the flow of the cold dense air.
I think some of the smoke was just drifting back down in the other chimney.
Anyway, I'll get a CO detector down there. It's possible my smoke alarms are CO also, I'll have to check, they are bran new 2 years ago so it's possible
thanks all