Smelling smoke from my blower fan?

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dstover

Member
Jan 21, 2010
41
south central Washington
We're getting some smoke in the house (not a lot, but detectable when you step into the house from outdoors) and having difficulty diagnosing the issue. When I put my face in front of the blower fan attached to the back of our BK Princess, the air coming out smells a little smoky, but how can that be? That air is not circulating through the firebox; it's just a heat exchanger, right?

The stove is 12 or 13 years old and has a straight-run 6" pipe through a cathedral ceiling with plenty of pipe elevation above the roof. The chimney was replaced two or three years ago and was cleaned last month. We're smelling less smoke since the cleaning, but it's still there. We asked our chimney sweep to check the door seal, and the handle shuts more tightly now, so I don't think that is the problem. And our cap, which used to clog up a lot when we had a bird screen, looks clear.

The intake for the stove is a duct that goes through the tile floor and draws "outside" air from the crawl space below the house. So we're not creating negative pressure that sucks smoke out of the stove, right? In any case, there's nothing new about that part of our setup.

Our wood is dry and lights easily. We are only smelling smoke after the fire has been burning for a while, the cat lever flipped, more burning, and then the air intake dialed back for the night.

We installed a mini-split in 2021, and the air handler is located near the stove. The mini-split can heat the whole house most of the time, so we're not burning wood round-the-clock as we did for our first 30 winters here. Sometimes we don't use the stove for several weeks at a time. But we still need it for when it gets below 20 degrees (to supplement our lone mini-split unit), or when we have a power outage (frequent in our area), or when we're pinching pennies, or when we just want to treat ourselves to the warmth of a wood fire.

Could the mini-split somehow be affecting the stove draft? It's near the stove and shuts down once the stove is producing a lot of heat, so I don't see how it could be causing a problem. But it's the only significant thing that has changed in the past year.

Any suggestions about how to diagnose this problem? It's only happening when the air intake is low (after the fire has been burning well for a while), so it seems like a problem that is related to air pressure in some way. If smoke isn't leaking from the stove's door, where else could it be coming from? Is there any way it could be coming out of the blower fan, or am I just smelling it there because that's where the air flow is strongest?
 
We're getting some smoke in the house (not a lot, but detectable when you step into the house from outdoors) and having difficulty diagnosing the issue. When I put my face in front of the blower fan attached to the back of our BK Princess, the air coming out smells a little smoky, but how can that be? That air is not circulating through the firebox; it's just a heat exchanger, right?

The stove is 12 or 13 years old and has a straight-run 6" pipe through a cathedral ceiling with plenty of pipe elevation above the roof. The chimney was replaced two or three years ago and was cleaned last month. We're smelling less smoke since the cleaning, but it's still there. We asked our chimney sweep to check the door seal, and the handle shuts more tightly now, so I don't think that is the problem. And our cap, which used to clog up a lot when we had a bird screen, looks clear.

The intake for the stove is a duct that goes through the tile floor and draws "outside" air from the crawl space below the house. So we're not creating negative pressure that sucks smoke out of the stove, right? In any case, there's nothing new about that part of our setup.

Our wood is dry and lights easily. We are only smelling smoke after the fire has been burning for a while, the cat lever flipped, more burning, and then the air intake dialed back for the night.

We installed a mini-split in 2021, and the air handler is located near the stove. The mini-split can heat the whole house most of the time, so we're not burning wood round-the-clock as we did for our first 30 winters here. Sometimes we don't use the stove for several weeks at a time. But we still need it for when it gets below 20 degrees (to supplement our lone mini-split unit), or when we have a power outage (frequent in our area), or when we're pinching pennies, or when we just want to treat ourselves to the warmth of a wood fire.

Could the mini-split somehow be affecting the stove draft? It's near the stove and shuts down once the stove is producing a lot of heat, so I don't see how it could be causing a problem. But it's the only significant thing that has changed in the past year.

Any suggestions about how to diagnose this problem? It's only happening when the air intake is low (after the fire has been burning well for a while), so it seems like a problem that is related to air pressure in some way. If smoke isn't leaking from the stove's door, where else could it be coming from? Is there any way it could be coming out of the blower fan, or am I just smelling it there because that's where the air flow is strongest?
Perhaps the fan creates a vacuum in some joint of the stove and draws some smoke from it?
 
It’s been fine for ten years. What could have changed? Well, you replaced the chimney and now it smells like smoke for the first time. Is the new chimney the exact same configuration as the old?

It has nothing to do with the mini split. Did you do any other work to the house?
 
No, we have not done any other work to the house.

The "new" chimney is not the exact same configuration as the old chimney, which was an 8-inch chimney with an adapter connecting to the 6-inch stove pipe below. The "new" one is a 6-inch chimney connected to the 6-inch stove pipe. Also, the "new" chimney is attached to our steel roof with metal flashing and caulking, rather than a rubber boot. But again, we replaced the chimney several years ago without experiencing any smoke issues afterward.
It’s been fine for ten years. What could have changed? Well, you replaced the chimney and now it smells like smoke for the first time. Is the new chimney the exact same configuration as the old?

It has nothing to do with the mini split. Did you do any other work to the house?
 
Well you certainly have been getting smoke since the replacement of the chimney but when did you begin to notice it? You wrote that the recent cleaning helped.
 
Well you certainly have been getting smoke since the replacement of the chimney but when did you begin to notice it? You wrote that the recent cleaning helped.
Yeah, sorry I wasn't clear about that! We've smelled some smoke toward the end of the season, and noticed that the stove didn't seem to be drafting well. But until this year, that problem went away after annual chimney cleaning.
 
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The blower fan? But it's the same blower we've used for years. No change there.
I wonder if blower creates some negative pressure, I understand that for years all is well, maybe some joints, it still doesn't hold. Is it the case to try without blower for a day?