House filling up with smoke!

[Tommymc]

I've been using the same original VT castings Parlor Furnace model 1A1 since I moved into our home 35 yrs ago. There have always been very occasional puff-backs under certain atmospheric conditions, but generally the stove operates well. Last winter, we started getting smoke in the house, sometimes from puff-backs, but just as often, it's unexplained. This happens essentially every time we fire up the stove. It's driving me nuts trying to diagnose and solve the issue.

I've cleaned the chimney, and a visual inspection shows it unobstructed. The flue is lined with rectangular clay (12x8?). I've thoroughly cleaned the stove and pipe. This includes vacuuming out the air intake holes, and behind the fireback. The fireback itself has been replaced 2x and is in good shape. This year, I replaced all the door gaskets and inspected the entire stove.

The only change I can think of is that through the years, we've tightened up the house (log home). A few years ago we added a pretty tight addition and replaced some old windows and doors. My first thought was that we aren't getting enough replacement air, so I tried cracking a nearby window (self defeating in cold weather). The house is still getting smoky. When I open the stove door to add wood, the smoke is still going up the chimney, appearing like there is a good draft. The chimney is in the center of the house, and I've sniffed around all exposed areas trying to detect leaks, but I really think the smoke is coming from the stove itself. I know there must be something I'm missing, but I'm running out of ideas. Why now after 35 years of great operation? Any suggestions are welcome.

 

[Whitenuckler]

I've been using the same original VT castings Parlor Furnace model 1A1 since I moved into our home 35 yrs ago. There have always been very occasional puff-backs under certain atmospheric conditions, but generally the stove operates well. Last winter, we started getting smoke in the house, sometimes from puff-backs, but just as often, it's unexplained. This happens essentially every time we fire up the stove. It's driving me nuts trying to diagnose and solve the issue.

I've cleaned the chimney, and a visual inspection shows it unobstructed. The flue is lined with rectangular clay (12x8?). I've thoroughly cleaned the stove and pipe. This includes vacuuming out the air intake holes, and behind the fireback. The fireback itself has been replaced 2x and is in good shape. This year, I replaced all the door gaskets and inspected the entire stove.

The only change I can think of is that through the years, we've tightened up the house (log home). A few years ago we added a pretty tight addition and replaced some old windows and doors. My first thought was that we aren't getting enough replacement air, so I tried cracking a nearby window (self defeating in cold weather). The house is still getting smoky. When I open the stove door to add wood, the smoke is still going up the chimney, appearing like there is a good draft. The chimney is in the center of the house, and I've sniffed around all exposed areas trying to detect leaks, but I really think the smoke is coming from the stove itself. I know there must be something I'm missing, but I'm running out of ideas. Why now after 35 years of great operation? Any suggestions are welcome.

If it happens just when you first start the stove, the flue might be too cold. Try starting out with a very hot fire, just kindling, and warm up the flue first with warm inside air if you have a warm room.

 

[begreen]

The original Defiant is a great stove but even the best eventually need attention. The stove is very likely due or overdue for a rebuild. If one has not been done.

What's puzzling is that with good draft, normally the firebox is under negative pressure, aka a slight vacuum. Smoke should not leak out. Can you pinpoint the source and location of smoke? Is the smoke visible or more of a smell?

 

[stoveliker]

Do you have CO detectors on all floors?
If it's the (unlined) chimney that is leaking (smoke smell while having draft in the stove), you want good detectors.
And you may be able to pinpoint the floor where the source is.

Of course if it's single floor this won't work. Yet you still want them working...

 

[Tommymc]

The original Defiant is a great stove but even the best eventually need attention. The stove is very likely due or overdue for a rebuild. If one has not been done.

What's puzzling is that with good draft, normally the firebox is under negative pressure, aka a slight vacuum. Smoke should not leak out. Can you pinpoint the source and location of smoke? Is the smoke visible or more of a smell?

The stove came with the log home we bought in 1990. The house was built in 1978, so I guess the stove dates back to then. I noticed the fireback was cracked (a common problem on these) and for a few years, I just filled the crack with stove cement. Eventually, probably mid-90's, I bought the rebuild kit. The original Defiant had to be totally disassembled to replace the fireback. The conversion to model 1A1 allowed fireback replacement without total disassembly. So ground up rebuild in perhaps 1995. Then another replacement fireback in 2016. The cement sealing the channel looks to still be intact.

Every time I light the stove, I walk around it sniffing all the gaskets and joints. At first I don't smell anything. Eventually, the acrid wood smoke smell starts wafting through the room. Not enough to set off the smoke detectors, on of which is in the same room as the stove. Just enough smoke to irritate our throats. When I open the stove door to load wood, I can see the smoke and flames shooting inward with the rush of fresh air. Sometimes a slight smoke smell escapes, but I think that's from built up ash on the door itself. I guess the next step will be to sit next to it with a good book and wait for the smoke smell to start.

 

[Tommymc]

Do you have CO detectors on all floors?
If it's the (unlined) chimney that is leaking (smoke smell while having draft in the stove), you want good detectors.
And you may be able to pinpoint the floor where the source is.

Of course if it's single floor this won't work. Yet you still want them working...

That's a good point. Our CO detector is just around the corner in the hall...no more than 10 ft away. It doesn't display levels, just beeps if there's an issue...and it hasn't gone off. Neither have any of the smoke detectors, one of which is in the same room as the stove. So the smoke is below the threshold to trigger the detectors. Not visible, just a throat and lung irritant.

The chimney isn't unlined, it has clay flue liners.

They are admittedly coated with some stage 3 creosote, but not enough to substantially reduce the interior volume. If there were cracks in the chimney liner, my gut says the creosote would act as a sealant. I clean the chimney every fall, and inspect with a mirror about once a month.

As near as I can tell, the smoke originates in the same room as the stove and then slowly rises to the 2nd floor by way of the adjacent stairs.

My focus has been on poor draft, although I've yet to observe it. There is good draft when I light the fire, leaving the door slightly ajar until the fire gets going. This problem has loosely corresponded to some projects which tightened up the house. Five years ago, we punched through the living room wall (the room where the stove is located) and added a new 15 x30 kitchen. The new addition is well insulated and tight, although it has a lot of windows. It also added an exhaust fan which our old kitchen never had. BUT...I'm mindful of that and the smoke problem exists even when the fan isn't in use. Also, the smoke issue didn't arise until a year or so after the new kitchen.

Then we remodeled the original kitchen space, turning it into a mud room, laundry, and enlarged bath. This tightened up that space and replaced two of the original (c.1978) windows. It's probably the following winter that the smoke issue started. In the summer, when the bath or kitchen vent fans are going, we do get a creosote smell...indicating that the easiest route for replacement air is down the chimney. Mindful that is an indication of a tighter house than before, I've tried cracking a window in the laundry. It's about 15 ft from the stove, behind louver doors (so air can pass). It doesn't seem to help. Still, replacement air seems logically to be the most likely culprit.

 

[stoveliker]

Yes, that could be. Especially if the main floor has tightened up but higher floors are still leaky - the home will then act like a chimney too, with warm air rising and escaping thru leaks upstairs. This leads to lower pressures downstairs.

But not having a stainless steel liner (most certainly needed for safety and code) and having stage 3 creosote would mean I would be very hesitant to burn in that thing.

Creosote sealing gaps is the worst you can have . If you have a chimney fire, it'll escape the chimney sideways...

 

[begreen]

Is it possible that the smoke smell is not coming from the stove? It may be a good time to have a professional level 2 inspection of the flue system, looking for cracked flue tiles, creosote leakage.

 

[Tommymc]

Is it possible that the smoke smell is not coming from the stove? It may be a good time to have a professional level 2 inspection of the flue system, looking for cracked flue tiles, creosote leakage.

It's always first noticed in the same room as the stove.

 

[begreen]

It's always first noticed in the same room as the stove.

There's usually a vacuum in the stove from the draft. Check other suspects too like the stove pipe and chimney.

 

[stoveliker]

The facts are:
-sketchy chimney (no liner, creosote)
-stove drafts well (door open air rushes in)

I think it's not the stove but someplace above the stove.

I suggest that creosote may have run down into seams of piping and starts off gassing when it gets hot, stinking up the place.

So I'd take off all pipes inside and inspect them and the cleanliness of the connections.