Smells like chimney!

[El_Barbón]

Yep, smells like chimney down here. Which is odd, 'cause it never used to do that. 'Specially not during the summer.

Once upon a time, we had an old Fisher Baby Bear down here, in the basement, and we used it to heat the downstairs and first floor. Never had much of a problem with smelling smoke or chimney, unless we were using it and doing something wrong. Fast forward, and we installed a Vermont Castings Intrepid Flexburn, replaced the stovepipe (about four feet total, connected to a masonry chimney), and put on a chimney cap. Ever since, I smell chimney sometimes. It's not constant, but it *does* seem to happen more on hot days, which seems counterintuitive.

I can't quite tell if the odor comes just from the thimble where the pipe goes into the chimney, or the joint where it meets the stove, or from the stove itself. Any ideas?

Thanks much!

 

[begreen]

Might be negative pressure in the basement caused by windows opened upstairs creating a chimney effect. A whole house or attic exhaust fan would make it worse.

 

[EbS-P]

New VC has it been cleaned and how much build up was there?

 

[El_Barbón]

Might be negative pressure in the basement caused by windows opened upstairs creating a chimney effect. A whole house or attic exhaust fan would make it worse.

Maybe, but we've got the basement windows open as well. I'd think that the cooler air down here would keep the air in the chimney from descending. As an aside, in the winter, we have to crack a window when we use the exhaust fan in the kitchen. Even though the house is 90 years old, it's tight enough that the fan will pull air down through the chimney if all the windows are closed.

New VC has it been cleaned and how much build up was there?

It has. We've been using it for a couple of years now. At first, we had a lot of buildup--it's a lot less forgiving than the old Fisher was!--as we were learning to use it. But we cleaned the chimney right at the end of the last burning season, and it's burning a lot cleaner than the first year we used it.

It does need a gasket replaced by the box where the catalyst goes, so it's probably not quite as tight as it should be right now. Still, seems like that shouldn't make a tremendous amount of difference.

Also, today's about 10 degrees cooler than yesterday, and I'm not really smelling anything.

 

[bigealta]

Colder outside air will give better draft.

 

[El_Barbón]

Colder outside air will give better draft.

Oh, for sure. But in the summer, I'm wondering why hot outside air is descending into the cold basement through the chimney.

 

[begreen]

Possibly because the house interior is acting as a chimney. Rising air from the upstairs through open windows is creating negative pressure in the basement.

 

[El_Barbón]

Possibly because the house interior is acting as a chimney. Rising air from the upstairs through open windows is creating negative pressure in the basement.

Shouldn't that pull in through the windows, though? I've got a much larger cross-section of open window in that room than I do of stovepipe. Unless... I... have enough ventilation upstairs that the basement windows can't keep up.

So this problem might get worse, then, once we've got the upstairs finished and have a second floor with open windows too, then. Should I just pull the pipe and block the thimble during the off-season, then? Or be there a better way?

 

[stoveliker]

I do pull part of the pipe in the off season. Not for this reason but I'm closing off my stove and have a lot of damprid in it.

 

[bigealta]

Cold chimney air is falling down the flue.
Happens with my brick chimney in the center of my house every summer. That's why i close the draft lever on the stove to help limit it a bit.