Help - Smoke smell emerges days after fire

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rWentworth

New Member
Dec 22, 2021
8
Sacramento
I bought a house that has a wood burning stove insert and am having an issue a nasty smoke smell after a fire. I have had two inspections and one cleaning done and they assure me everything with the stove and chimney looks great. On my last burn, I didn't smell any smoke the day of the fire or the day after. I closed the damper the day after the fire and cleaned out the firebox. The 2nd day after the fire, the smoke smell emerged and is still lingering The smell seems to be strongest at night (maybe because I have the heater running). I'm at the point where I don't even want to use the fireplace if this is going to happen every time. I read that a damper cover that seals the flu might help but I'm not sure. Please help!!

[Hearth.com] Help - Smoke smell emerges days after fire
 
There could be a couple reasons why this is happening. One is that the stove doesn't have a full, stainless liner, the other is that the stove could be in a negative pressure area. Is it in the basement? Does the kitchen have a powerful exhaust fan? Does does the stove have a stainless liner to the top of the chimney?
 
There could be a couple reasons why this is happening. One is that the stove doesn't have a full, stainless liner, the other is that the stove could be in a negative pressure area. Is it in the basement? Does the kitchen have a powerful exhaust fan? Does does the stove have a stainless liner to the top of the chimney?
It does not have a stainless steel liner. I believe it is clay. The fireplace is In the living room. I cracked a window during the burn. No powerful exhaust fan in the area. I do have a heat pump with has a pretty decent draw when the heater is running. The intake for the heater is probably 30 feet away. The smell only appears days after a fire. Typically never the day of or day after.
 
If the stove is not tied into a sealed flue system then it should be. There is more than just a smell risk if it is not. Is there a CO monitor in this room?
 
If the stove is not tied into a sealed flue system then it should be. There is more than just a smell risk if it is not. Is there a CO monitor in this room?
I believe it is. There is a liner that attached to the stove and runs up the chimney. I have a CO monitor and I'm getting a reading of 0. I just don't understand why the smoke smell is coming days after the fire.
 
Would a flu cover the seals help my issue? I think I can feel a cold draft under the insert when it's not in use and the damper is closed.

Would does the smoke smell come days after the fire?
 
I believe it is. There is a liner that attached to the stove and runs up the chimney. I have a CO monitor and I'm getting a reading of 0. I just don't understand why the smoke smell is coming days after the fire.
OK, that is good. One possibility is that the chimney was not cleaned well before the liner was put in. If the liner is uninsulated it can cause residual creosote to smolder which is not good. But if this is days later it could just be a draft reversal from negative pressure developing in the living room. That would explain the cold air. There are a number of possible causes for this. Opening a window upstairs, leaky ceiling attic stairs or vents, multiple exhaust fans running (kitchen and bath or dryer running).

Or, does this just happen on windy days?
 
OK, that is good. One possibility is that the chimney was not cleaned well before the liner was put in. If the liner is uninsulated it can cause residual creosote to smolder which is not good. But if this is days later it could just be a draft reversal from negative pressure developing in the living room. That would explain the cold air. There are a number of possible causes for this. Opening a window upstairs, leaky ceiling attic stairs or vents, multiple exhaust fans running (kitchen and bath or dryer running).

Or, does this just happen on windy days?
I have only had a few successful fires so far and it seems to happen every time.
 
You could be smelling the chimney itself from a backdraft when the wind blows or furnace kicks on as it will "pull" some air as it runs and the fireplace chimney is cold. When a fire burns the draft is strong and you wont smell it then and the bricks/clay liners being warm keeps that draft somewhat..... I myself have just moved into this house and occasionally I get a whiff of smoke from the built in fireplace ( and we havent even used the fireplace yet ) it is clean, clay lines with some soot.. just being in the right spot at the right time you catch a whiff of phantom smoke. You may be smelling it more than you think as we dont pay 100% attention 100% of the time when subconsuness kicks in
 
What temperatures have the fires been? I had really bad smoke smells the next days after break in fires for my stove where it was basically smoldering the whole time. It didn't smell prior to the break in fire so I'm assuming a bunch of Creosote deposited in the stove/in the stove pipe and due to appliances causing negative pressure the smell was pulled into the house.

I've had no smells since burning normal temp fires and installing an oak for my oil boiler. Kitchen exhaust and dryer still pull air out of the house though. No smoke smell though.
 
Generally do fires when it's ~45 degrees or so. The fire was going pretty good and wasn't a smoldering fire. The smell has been getting worse each day. It really stinks now, and it has been 4 days since the fire.
 
This is something we can't tell over the internet. Also, there is something inconsistent here and perhaps some confusion. Don't burn until this is investigated. First response about whether there is a liner:
It does not have a stainless steel liner. I believe it is clay.
The second response was:
There is a liner that attached to the stove and runs up the chimney
It sounds like there is some uncertainty in this setup that needs to be cleared up. The insert may just have a stub of a liner that just goes past the damper area and not to the top of the chimney. It needs a certified professional sweep to inspect this setup. There could be combustibles in contact with the chimney that are smoldering. Even if there is a full liner it may not have been installed properly. If the chimney wasn't cleaned before installation old creosote may be smoldering. That can be very dangerous.
 
Mine would do this when it got very humid out, or if it rained and the wind blew rain down the cap. Even with the chimney cleaned there’s always residue. I just learned to live with it, it was only in shoulder seasons and in summer I’d open the windows.
 
This is something we can't tell over the internet. Also, there is something inconsistent here and perhaps some confusion. Don't burn until this is investigated. First response about whether there is a liner:

The second response was:

It sounds like there is some uncertainty in this setup that needs to be cleared up. The insert may just have a stub of a liner that just goes past the damper area and not to the top of the chimney. It needs a certified professional sweep to inspect this setup. There could be combustibles in contact with the chimney that are smoldering. Even if there is a full liner it may not have been installed properly. If the chimney wasn't cleaned before installation old creosote may be smoldering. That can be very dangerous.
I have the owner of the chimney sweep company coming out on the 29th to investigate. The tech that came out last time didn't see any apparent issues but said his boss would come if it happened again. I'm definitely not going to burn until I get this figured out,
 
I have the owner of the chimney sweep company coming out on the 29th to investigate. The tech that came out last time didn't see any apparent issues but said his boss would come if it happened again. I'm definitely not going to burn until I get this figured out,

Just read through this thread, any updates?
 
Ah well that's good something was found and hopefully fixed. Finding nothing would have been infuriating. Best of luck...let us know!
 
He found a gap where the clay liner meets the wood stove and sealed it
The insert should have a full liner. The clay liner typically starts 2-3 feet above the top of the stove.
 
The insert should have a full liner. The clay liner typically starts 2-3 feet above the top of the stove.
Ah good catch begreen. I totally skipped over the word 'clay'. Is this stove vented into a clay fluen or lined all the way up? That's almost surely your issue if it's not lined. Even a plain uninsilated steel flex liner would be infinitely better than nothing.
 
Of course, check the flue per all of the good advice you've received above. You need a solid flue for safety. And, woodburners tend to be an occasional use item in that part of CA, so you see a lot of "alternative" and downright unsafe installations. But if you still have a problem, I've been there.

I lived down the road from you in Livermore for a while. I had a conventional fireplace with the same problem. I had a few theories about what caused it. You can see if you think any apply to you.

1. The tendency for the weather to be 60 degrees +- 10. If everything is the same temperature, there is little positive draft, and maybe a negative when the fire is out and the masonry is cold, a day or two later. If the stove isn't sealed (and modern stove primary and secondary intakes generally don't seal) you're going to have a smoke smell when draft goes negative for whatever reason. The reasons my draft got negative follow.

2. A typically leaky California house. If there's no really cold weather, finding and fixing leaks isn't a priority. Though there were no obvious problems in our house, a good wind outside would cause helium balloons to blow around inside the house.

3. A tree wall perpendicular to the prevailing wind that created lower pressure at the back of the leaky house, along with the chimney flue being toward the front. Combine that with a leaky house and it's breeze in through the chimney, and out through the back wall leaks.

4. If it was cold (okay maybe 35-40!), and the chimney hadn't been used, stack effect would have cold air enter through the cold chimney and exit heated through the leaks in the taller second story, no breeze required.

Yes, my fireplace had a damper, that I closed, but it didn't seal perfectly, similar to the modern woodstoves with the always open primary and secondary air supplies. My stoves here in MT will give off a flue smell sometimes during the brief times during the summer when they're not in use, but it's not much of an issue since it's summer, the windows are open, and ventilation is good. If not in use during the winter, they have a good positive draft because of the warm inside air and the cold outside air. They're wasting good warm air up the chimney, but they don't smell inside.

I solved my problem in Livermore by simply not using the fireplace, except on the very rare occasions that I decided that a fire was worth a week or two of smoke smells. Annual heating bills were less than $40 anyway, and since it was a fireplace, it made the house colder overall when it was in use. I realize that isn't the solution you're looking for, but I decided not to install an insert in my fireplace (though I would have liked the ambiance) because I concluded that unless I could seal the drafts, it wouldn't have solved the problem. Though I probably could have come up with a burner that would fit, and that I could seal up somehow when not in use, a little ambience, and offsetting less than $40 a year in heating bills, never got the issue far enough up on the priority list to get done.

If you have a sealed flue, the problem will stop if you can seal the stove when it's not in use. The thing is, that's impossible to do with the design of a lot of inserts. If you can access yours, masking tape, plugs, plastic wrap, or whatever works applied to ALL of the draft inlets should solve the problem. Other than that, my experience says the smell pretty much goes away a few weeks after the last fire, or when you light another one.

In that part of the country, I think a woodstove is fun (or not), and good to have as a SHTF backup, but a heat pump makes sense.