Help! Ash-like smell for days after burning a fire

kellysmith619

New Member
Nov 10, 2019
3
0619
Hello! I am hoping to get some answers to our fireplace woes. We purchased this 1993 home exactly a year ago. We have noticed that every time we burn a fire, the house smells like ash or campfire for a few days after, despite cleaning out the ash from the chimney. We have had the chimney inspected 2 times and cleaned once. The inspection comes back clear, and they say that there isn't creosote build up. Last week we had a top seal damper put on to help with the downdraft, but the problem actually seems worse since then.
Some more information:
-The chimney is along the exterior wall of a 2 story (plus attic) house, and it goes all the way to the top (no height issue).
-We live in Indiana, so the outside temperature is already cold, and it is making the chimney air cold.
-The ash smell seems to lighten during the day when the outside temp warms up, so it is definitely related to temperature.
-Since the top damper was installed, there is a cool draft that comes in.
-There is NO smell at all when the fire is lit, and we don't have trouble actually lighting it.
-The smell typically goes away after 3-4 days, though we are on day 4 with this time and it isn't showing signs of going away. This is our first fire since the top damper was installed.

Here are my questions:
-Are there any affordable solutions to this problem? We already spent a lot on the top damper, and it just made the problem worse. I would hate to keep tossing money at this to have the same result.
-Possible solutions I have come across - adding an insert with an insulated liner, just adding an insulated liner to our current fireplace, airtight doors.....any thoughts on these? I fear that we would spend $$ to add an insert and insulated liner, and would still have a downdraft issue bc we never really fixed whatever is causing it.
-Can you have downdraft issues with inserts?

Thanks so much for helping us trouble shoot this. We are pulling our hair out, and it seems that the fireplace companies we have talked to are as confused as we are.
 

snaple4

Member
Dec 18, 2017
156
AR
Ash smell would likely be from a downdraft after the fire. Couple problems I see with this: 1-It isn’t in a basement and has a tall flue so I would be hesitant of saying you have a downdraft. 2-the tall flue should have enough pull on it to be sucking air out of your house all the time. 3-If a top damper was installed correctly then you should have minimal to no outside air coming in.

Do you still have your damper at the bottom? It is possible the air is circulating inside the chimney with the top damper closed. Do you have two fireplaces by chance?
 

kellysmith619

New Member
Nov 10, 2019
3
0619
Ash smell would likely be from a downdraft after the fire. Couple problems I see with this: 1-It isn’t in a basement and has a tall flue so I would be hesitant of saying you have a downdraft. 2-the tall flue should have enough pull on it to be sucking air out of your house all the time. 3-If a top damper was installed correctly then you should have minimal to no outside air coming in.

Do you still have your damper at the bottom? It is possible the air is circulating inside the chimney with the top damper closed. Do you have two fireplaces by chance?
Thank you for the reply! They removed the bottom damper when installing the top damper. We only have 1 fireplace in the house. There is definitely a draft of some sort coming in....is it possible for cold air to seep in through the bricks? The inspections have said the chimney looks great though.
 

snaple4

Member
Dec 18, 2017
156
AR
Thank you for the reply! They removed the bottom damper when installing the top damper. We only have 1 fireplace in the house. There is definitely a draft of some sort coming in....is it possible for cold air to seep in through the bricks? The inspections have said the chimney looks great though.
can you feel the cold draft from the fireplace/chimney itself or does it seem to come from holes in the brick around the fireplace?
 

Woody Stover

Minister of Fire
Dec 25, 2010
10,781
Southern IN
You may have "stack effect" in the house. Warm air exits the upper part of the house and draws replacement air down the chimney. I don't know about top dampers, but they may not completely seal the top of the chimney. You can lessen stack effect by reducing air escaping the top of the house. Make sure there are no open or leaking windows upstairs, seal the attic access, seal ceiling light fixtures (I'm not sure how to safely do that.)
 

snaple4

Member
Dec 18, 2017
156
AR
, seal ceiling light fixtures (I'm not sure how to safely do that.)
you can move the insulation away and then build a box around the light making sure to keep proper clearance. Then you air seal the box. Not very fun but very effective. We use HVAC duct board when we have to do it for a customer. I know some people use wood but that takes way to much time for me.
 

kellysmith619

New Member
Nov 10, 2019
3
0619
Thank you for the suggestions. He did come and confirm that it is a pressure issue. When our hvac unit kicks on, it pulls air from the fireplace. I am curious why the smell disappears after 4 days though, even though the hvac unit continues to run. Also, he really offered no solutions, other than converting it to a gas fireplace insert, which comes with a hefty price tag.
 

spudman99

Member
Jan 26, 2018
175
Yardley, PA
I used to have a fireplace smell before I installed my insert. Had a top spring loaded cap with a wire to pull it down to seal. There are several issues here at play that may require a coordinated effort to remove or abate the odor.

1. Even though your chimney has been cleaned, there will always be residual creosote on the flat surfaces, or stuck to the mortar that binds the liner in place. Think of dirt on your car that you removed by blowing on it. It looks clean but there will always be a light layer of dust.

2. Air moves up or down based on two factors: temperature and barometric pressure. Cold air sinks, hot air rises. You see less odor during the day as the chimney warms up and the hot air rises. Opposite in the evening as the cold air sinks in the chimney. Even if you seal the top of the chimney, air that remains inside will rise or fall and that can bring an odor into your living space. Same for pressure, when the barometer decreases somewhat suddenly, low pressure allows air to sink and thus cause the same problem even in warm weather.

3. Sealing the bottom of the chimney will stop the issue, but then the fireplace essentially is unusable. That does not seem like an option for you. One way you can help stop the odor is to leave the top sealing damper slightly open. This will allow warm house air to rise in the chimney and escape out the top, taking the odor with it. Then of course you are constantly loosing some household heat. Others have resorted to burning a candle in the fireplace to create some heat for an updraft, that is not practical for everyday use. One final suggestion that worked for me. When my traditional fireplace was not in use and was cool, I closed the fireplace doors and cover them with a fleece blanket (with our favorite college football team logo). that stopped all of the cold drafts and the smell, trade off was looking at the blanket.
 

Woody Stover

Minister of Fire
Dec 25, 2010
10,781
Southern IN
Maybe the furnace can be fitted with its own outside combustion air supply, so it won't pull air from inside the envelope of the house? I'm not sure, maybe someone will chime in. Also, use the forum search feature.."fireplace chimney odor," "chimney downdraft" or similar terms.