HELP! Ongoing chemical smell in room above wood burning insert

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emann

New Member
Mar 5, 2024
4
IL
We own and live in a 120yr-old house which is separated into two flats (we live upstairs and have tenants downstairs) and nearly 2 years ago we had Regency wood burning fireplace inserts installed in both units, so that each unit has a functional fireplace and insulated liner. The chimneys are separate but run right next to each other, so the second floor fireplace is almost right above the first floor one.

We LOVE LOVE LOVE our insert, use it all the time, BUT any time there is a fire in the *first* floor insert, we get major chemical smells seeping into our living room from our fireplace. It’s *not* smoke or fire smells, it is a strong chemical smell. (Our CO detector has never alarmed.) We have to open all the windows, and close off the living room from the rest of the house until it dissipates. It is strong enough that it makes us nauseous, sometimes even makes our eyes burn if it really gets going. The chemical smell happens *any* time they make a fire, about 30 minutes into burning, and it tends to get worse from there until we have them let the fire die. It happens whether we are also burning a fire in our fireplace or not. It does not happen more or less dependent on the weather. There is never a time they have made a fire when we have not been able to smell the chemical smell up here. Again, it’s not a Smokey fire smell! It smells like chemicals. Before the inserts and liners, we were building fires in both fireplaces (upstairs and down!) for years and never had any weird (or even smoke) smells or anything like that.

What on earth is happening and how do we make it go away?!? Our chimney/fireplace guys who installed the inserts and liners seem to have no idea what we’re talking about, and have no idea how to solve the problem.

We have been making fires for the past 2 winters, so this is no longer a brand new install. Here are things we/they have *already tried* :
-LOTS OF first floor fires (Assuming perhaps it’s burn off from the newer liner?), letting them burn for long periods at very hot (either when we are out of town/out of the house/or just don’t need to use the living room and can close it off from the rest of our unit)
-stuffing the front of our insert in any places where you can feel a draft (we did not do this ourselves, our fireplace guys did it with special insulation). That helped for a short amount of time (maybe 2-3 fires), but the smell returned after that.
-chimneys cleaned
-raised the cap on the first floor chimney (the chimney caps were already staggered but they lifted it about 2 feet thinking perhaps they weren’t staggered enough and we were getting some sort of down draft from the other chimney in such close proximity)

Any other ideas??? Any idea what’s happening or most importantly how to solve the problem? The only solution I can think of is to not let our tenants use the downstairs fireplace at all/consider it non functional, but we spent thousands on the insert and the liner, that feels like such a sad waste of resources!!!

If you have made it to the end of this post BLESS YOU and thank you so much for helping me problem solve!!
 
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Is there an air sealed block off plate in the second floor (your) insert?
If something gets hit because of their flue, and that can get down to your insert, you could smell it.

Are the liners insulated? It sounds like something (plastic?) is getting hot from their liner.
 
Just some thoughts:

Smoke from a modern stove can have a chemical smell once it's up to temperature - which is about 30 minutes in, as you mention, and it doesn't smell anything like a campfire. You might see if you can get downwind of the chimney and see if it smells the same.

Is your insert using an OAK (outdoor air kit)? Could you be pulling air and smell from outside through that or through some outside air leak into the living room?
 
Chemical smell is normally the stove reaching a new high temp.
Would this happen in perpetuity though? Forever, or just initially? We’ve had that first floor fire going hot for long periods of time multiple times but it happens even at the beginning of a fire down there.
 
Is there an air sealed block off plate in the second floor (your) insert?
If something gets hit because of their flue, and that can get down to your insert, you could smell it.

Are the liners insulated? It sounds like something (plastic?) is getting hot from their liner.
Hmm I’m not sure about an air sealed block off plate, I will definitely ask our installer about this. He has told me the liners are insulated. Thank you for your thoughts!
 
Just some thoughts:

Smoke from a modern stove can have a chemical smell once it's up to temperature - which is about 30 minutes in, as you mention, and it doesn't smell anything like a campfire. You might see if you can get downwind of the chimney and see if it smells the same.

Is your insert using an OAK (outdoor air kit)? Could you be pulling air and smell from outside through that or through some outside air leak into the living room?
Ooh I’m not sure about an Outdoor Air Kit, I can ask. Thank you!
 
We own and live in a 120yr-old house which is separated into two flats (we live upstairs and have tenants downstairs) and nearly 2 years ago we had Regency wood burning fireplace inserts installed in both units, so that each unit has a functional fireplace and insulated liner. The chimneys are separate but run right next to each other, so the second floor fireplace is almost right above the first floor one..

What on earth is happening and how do we make it go away?!? Our chimney/fireplace guys who installed the inserts and liners seem to have no idea what we’re talking about, and have no idea how to solve the problem.
Are both flues terminated at the same height? If so, one may be siphoning smoke into the other. Can you post a picture of the chimney top?