Try checking the draft on your chimney for those of you who have a chimney, If you have a back draft problem or any obstruction you could be getting more of the combustion gasses in the house than you realize. If it were a natural fire, perhaps it would be smoking the room out, but since it is a gas log the only thing that happens is a bad smell.

A quick test with a small wad of newspaper in a tin can or even a match will give you an idea of how much draw the unit has. A leaky house can cause a chimney to back draft as well as a bathroom or kitchen exhaust fan. A really tight house will vent poorly because there is no excess air to flow up the chimney. In this case, the simple fix is to slightly open a window.

Sometimes we tend to think a gas log doesn't need much venting, but just like natural fireplaces, no matter how hot the fire, it can back draft if conditions are just so.

Thanks DK &Sons, my propane stove is ducted directly thru the old chimney to the outside. It does not vent up the chimney but out thru it with a vamp the cap outside. I just cannot understand this smell problem but it sure seems like it is a common one based on the comments. Maybe it is the sealant between the duct and the brick where it goes thru the old chimney, or maybe a bad seal in the glass. It's a real head scratcher that's for sure. I wish now I had kept my old Jotol wood burning stove!

Any of the conditions I described can cause a back draft on an appliance that vents to the exterior. Check the draft, it takes less than a minute to confirm air is moving out vs. in.

We got our old insert replaced with this one over the summer, new mantle and all. I am burning it now for the second time and that self cleaning oven stink is starting again. The other day I had it going for six hours and my house stunk for 3 days! No fan unit this time so it can be used during a power outage. Was that a mistake?

I'm glad I found this thread. Its getting chillier in northeast PA and once again time to fire up my 2 propane gas fireplaces for winter use. I have a Heat n glo on the main floor and a martin unit in my basement. Both were installed brand new in 2005. They both have to be burnt off for 10-12 hours for the first time during the season. Today, that Self-cleaning oven smell was so strong giving my wife and I a headache. Enough is enough! We are talking 11 years already. None of my friend's units have these odors. I've called dealer many times about this and they have no answers but could it possibly be the installation? I find it strange that 2 different manufacturers produce the same smell, and this many years out too? So every year I burn both off using 12 hours of propane and then have to use them weekly just so when I want to use them for the occasional ambiance they wont smell. All the while, my gas company is laughing all the way to the bank. Cost me $6K in 2005 and I'm about to not even use them to spite my gas carrier who originally installed them. Has anyone had any luck with the manufacturer themselves? I'm afraid both the dealer and manufacturer will both blame each other and I will get nowhere. I'm calling them tomorrow.

Have you had them serviced and/or cleaned?

I know some of these post are old. I have a vent less fireplace, and also a small kitchen stove that run off of propane , We use these as back up when the electric is off. There is no smell when I use the kitchen stove, but when we light the fireplace there is an odor, we get headaches and eyes burn. We replaced the logs, and still the same thing, anyone have any ideas as to what our problem may be ?

Donna your problem is that it is ventless. Do a search on ventless gas fireplaces and the health issues they can cause

Started up the gas stove (Lennox) today after not using it for about 3-4 weeks. Same horrible smell once again! Smells like kerosene or burning oil. Hard to describe other than it is very disturbing. Dusted off the stove before startup but still the strong, strong smell. Does not seem to be dust in my mind because it seems so caustic! Wondering if anyone has a similar Lennox or other type of stove with the same problem and can recommend a fix. Could it be the glass door leaking past the seal? What a waste of $5k this stove has been over the years! Can't even seem to get in touch with Lennox because their web site seems to be structured only for Commercial sales.

We just had an Empire Heritage direct vent cast iron stove (27000 btu) installed on 3 season porch. The first day burning I would rate the smell a 10 out of 10 But being a 3 season porch, we closed the door into the house and after around 20 hours of burning I would now rate the smell about a 2. I don’t know what we would do if had this inside house. It’s currently 12 degrees outside and a comfortable 70 on porch. Only took about 1 hour to go from 35 degrees to 70

Exact same issue!

Has anyone tried changing out the logs and/or the burner unit to see if that solved the bad/chemical smell when the fireplace is on?? Mine does not seem to be "burning off." I'm wondering it it is something in the fireplace unit itself, or if it is something in the house construction that is off-gassing when heated up by the fireplace.

We just replaced our vent free gas logs with new (expensive) vent free gas logs and are still having this problem! Terrible chemical odor...I am extremely frustrated & don't know where to turn!

Purchased vented gas log fireplace. Installed January 2018. It took about 30 burn hours until odor was gone. fortunately Ours is on a indoor porch so we could close door to porch and let burn. A few weeks ago we fired it up for first time in many months. First 3-4 hours burning it small led again but then went away.

I just signed up to follow this thread however I have a slightly difference problem. I have Vermont majestic direct vent natural gas fireplace that came with the house I bought and is around 14 years old. My problem is that my eyes burn when using the fireplace, with or without fan on. Yes I have a separate switch for blower fan. I have plugged in CO detector right next to it, no alarms at all. I did get a slight headache but that could be due to me not sleeping good the night before. My wife didn’t notice any headaches but she did notice burning eyes. One thread mentioned it could be the sulphur from sloght unburnt gas. Anybody else having this issue?

I ordered a gas leak detector and found out slight gas WAS leaking from the fireplace gas line. i fixed it and now all is well!

Can you tell me where you ordered gas leak detector? Amazon? We have a ten year old house we are renting. There is a gas fireplace in the living room. I’d say 90% of the time if not every time there is a smell coming from the fireplace. The landlords “heat person” has come twice and said it’s just dust burning off. He kept saying it wasn’t carbon monoxide to which I said I knew that- and have a monitor next to the fireplace for it already. Maybe it’s a gas leak? My thoughts are it could be: Glass is not flat against frame causing a leak, logs are too old and somehow giving off smell, it really is just dust, the wood mantel above it is heating up and causing an off gassing. Would love anyone’s thoughts!

Similar issue to Alia Rodriques, having recently moved into an older home with a gas fireplace that’s probably 10+ years old. I too would love to know where I can find a good quality gas leak detector.

We've had a ventless propane gas log fireplace for several years with no problems but this winter ive noticed that burning eye,headache kind of oder. Could there have been a change in the chemical makmakeup in todays propane? Is there a certified gas technician that can advise a solution? Apparently its a somewhat common problem so someone should have an answer.

Very interesting thread I have a direct vent gas fireplace. was installed in 2006 serviced and cleaned every year. ran fine up until 3 years ago then started getting that oder from it giving headaches and burning eyes. had it serviced couple times since, they told us that smell was from a bad gasket. went to get the gasket replaced, was told it was good from a different service provider, they came and looked at my fireplace tested for gas leak, was fine. Tested for carbon monoxide was fine. told me it was refractory smell and was nothing they could do about it. Said I may need to replace logs or Firebox itself. I'm up in arms any help would be appreciated.

I find this fascinating. Clearly something is wrong with these units (or the gas itself?) And it's across manufacturers and installers - yet in so many cases no one seems to know what is causing this smell or how to get rid of it. We just had a Napoleon unit installed and we have the same problem. I don't think we fully executed the "curing" process so we'll plan a day to open all the doors and windows, put our animals and kids somewhere safe and try to burn it out.

We purchased a 20 year old house in an expensive neighborhood about five years ago. I hardly used the gas fireplace because the smell gave me a headache. Just this week, a friend suggested that the problem might be the fake logs. I removed the logs and turned on the fireplace. Sure enough, the smell was gone. It may not look pretty, but at least I can warm up the room without getting a headache.

That’s really interesting. I’ve never tried it witho the fake logs. Our smell goes away after several minutes but it’s still offensive. Burning it in at the start of the cold season doesn’t do anything. If we don’t use it for more than 1 day the smell comes back. It’s ridiculous for the price one pays.

I read somewhere else (possibly here on houzz) that the logs should be replaced approximately every 3 to 5 years. And I see people here are also being told that their logs might be the problem. So, what is it that breaks down in these logs over time? What are the specific components that have a 3-to-5 year shelf life and require frequent log replacement? It seems to me that good quality ceramic logs should be lasting longer than that.

Good question. It’s interesting about the logs because we never had a smell problem the first 4 or 5 years we owned the stove. It’s just been the last 3 or 4 years. Buying new logs will not only be a likely costly venture but also one in regards to where the heck you can buy them. We have a Lennox stove and I bet I could reach the Pope easier than them!!

Sorry for the late response as I don’t check the emails regaeding this thread often. Here’s a link from amazon for the tool that helped me. in my case, he has pipe was taking a sharp 90° turn and that’s where the leak was. I’m going to share the picture too. Don’t let anybody say you’re instincts or your feeling is wrong. I was inhaling natural gas and that’s why I had the symptoms. In my case it wasn’t carbon monoxide. I hope this helps. Take off the glass and check the seal around it, if it’s coming loose or doesn’t look good, require your landlord to replace it. God Bless.

Leak Detector

Carbon Monoxide detector

I bought a home (15 years old) this fall that has a ventless fireplace. I've never had one before, so know nothing about it. The inspector said everything was fine. I had the gas company come out to help me turn on the pilot light. The damper is permanently closed shut. However, every time I turn it on, there is a propane smell in the house after about 30 minutes. Is this normal?

I will never understand the concept of ventless fireplace. all fireplace should be vented one way or another (I’m a homeowner not an expert). You should never be able to smell propane, that’s not safe, period. I had a very slow natural gas leak and I could feel effects of it. Thas my 2 cents.

We have a gas log fireplace in a home we are renting that has the exact same “melted wax” smell.

my theory is that the paint which is on the mantel is latex, giving it the “warmed plastic” odor that you get if plastic is melted. I think paint should never be used on a mantel for this reason. It gets hot by the heat rising and released those chemicals in the air of your home.

I am just as exasperated as the others. We built our home in early 2015. We have a gas fireplace with NO logs...it has these fake glass chunks or something in it. (We didn't know it at the time.) I recently moved them all out of the flame and it doesn't appear to be helping. We didn't use it for the first few years as we had turned the gas off and could never get it relit. Last year I had someone out to service it (basically just needed more patience as there was just a lot for air in the line) but since then we have been unable to run it without getting massive headaches from the smell. I am running it again today with all the windows open for hopefully a good 8+ hour span but I feel I have run it collectively for a ton of hours. If this is just "how it is" I am going to go crazy. This fireplace was such a thing during the build and now to not be able to use it??? So awful!

I posted here in Jan 2018. i have vented fireplace. like past 3 years I fired it up For first time since early spring. Same awful odor. Opened doors and let it burn for 5 hours. and like past 3 years, I would say 85-90 % of odor is gone.

Thanks so much Ed for responding as I know how long ago this was started. Sadly ours doesn't have doors. It is still vented to the outside from what little I know and can see but sadly your solution won't work for us.

We have a new gas stove, not an insert but a free standing one. The 'factory' smell of burning paints or oil coatings was strong in the first hour despite having windows and doors open. 24 hours later there is still a noticeable smell though not as bad. By comparison, when we had a normal furnace installed in the old house there was no smell. The 'factory' smell might be dangerous, how would you test it?

Old post but I wanted to comment.

I have a heat n glo direct vent propane stove. The burn off smell is brutal, but mine faded after burn in.

BUT. there is always this sorta smell. I have a hard time figuring if it’s fumes or off gas from metal? Someone above did say that the mantles that heat up may produce an off gas smell/sorta metal smell. I think that may be what is happening with me.

I bought a CO2 detector and have it plugged in near the unit and there doesn’t seem to be a problem there..

I also have a brick fireplace around the unit and painted it a few years back. So I often wonder if it’s making the paint off gas?

Thank you so much for responding. The mantle is something I thought about from the post, but it is essentially the same brick as the whole fireplace is faced with. However, inside is metal. You know how some gas fireplaces still have stone "walls" inside where the gas log or rocks or what not are? I worry this may either go on a long time or may just always be that way. This fireplace has been a cluster from build thru now 5.5 years later. We may just replace the gas insert or I guess continue to not use it. So sad and aggravating.

The inside of my hearth opening is metal as well. But my mantle is this massive 40lb metal sorta blacksmith looking thing that Came with the heat n glo and it def gets quite hot .. so idk

Does your unit not have a metal mantle that attaches to the faceplate on the front?

Hi Danny Boy. We wound up unhooking our (vents outside) fireplace from the propane tank, and just letting it be decorative. Sadly. A week or so ago during a rain storm I thought I heard some rain drops getting in there. It's possible that is happening occasionally, leading to rust, leading to smell during use. But I didn't want to sink $$ into a new log/burner unit only to find it was still smelling due to something else (like mantle material or building adhesive) so I gave up. Best of luck with yours!

Yeah that sucks. I wanted to switch because I was so tired of firewood and EVERYTHING that goes along with it from the labour, the smoke.. did I mention the labour??

I had a Vermont Castings vented gas insert from 2000. It smelled awful from the start. Burned it for 24 plus hours in the summer with the windows opened. Not much help. I had it replaced with new Vermont unit - dealer burned it for 24 hours at there shop. Still stinks after installation. Same nauseating chemical burning smell. Can no longer turn it on without headaches and awful smell. I heard Vermont went out of business. I think it is coming from the steel itself. Need to decide if I keep it as a non- functional decoration or replace it with a different companies insert.

That’s a real shame. Our direct vent Lennox after 8 years still has the smell of we don’t start it every day. If we use it every day, even for a few moments, the smell is a non issue. If we miss a day of use the smell is back and lasts for 15 minutes or so. I have a feeling that it’s the artificial logs. Very annoying and something I think a company and prestigious as Lennox should have an answer for!

Interesting discussion! We are about to install a Valor (no fan) insert. From what I understand, there should be no smell because the unit is enclosed behind glass and it vents directly through the chimney. Has anyone experienced a smell with those?

Terrible burning plastic smell after replacing glass and gasket on older propane fireplace. Permeates house. Have tried burning it off for 12 hours without resolving, even with all doors, windows open and fans on. Is this toxic? Feels so. Headaches and sore throats. Stove guy says it needs to off gas a ”couple hours.” Anyone have this and will it resolve?

My gas insert with logs/fan(4 YEAR OLD) always stinks at beginning of season. Takes around 8-12 hours of burning until smell goes away (98% goes away). Then all good as long as we use it every few days. As for replacing the glass and gasket causing the smell? Prior to replacing those, did you use it without an odor?

Our stove is a Lennox direct vent propane type and about 8 years old. We get this smell at the start of the season for about an hour or so. Then if we use stove every day it is fine. BUT, if there is even one day we do not use it the smell returns for about 20 minutes. Some day I am going to change out the logs to see if they are the issue because they are ceramic. It’s a very annoying issue and one that Lennox and others should address but those big companies won’t come to the plate!

@theberm40 it really depends. We have a similar set up. In 2019 I ran it for several consecutive days in the fall to "burn it off" and it didn't work so we didn't use it that winter. In 2020 I ran it again for consecutive days 10+ hours and did multiple sessions as soon as it was cool enough to have the windows open and it never burned off so we again couldn't use it this past winter. Obviously some say they experience it every first start up and/or if they don't use it daily but that hasn't been the case. Right now it is just a useless decoration.

Hi,

I had a new home built in 2016 with Heatilator fireplaces and I have not been able to use them due to the smell! I was told to just burn them off and after I tried to do that with the fireplace in mr bedroom I developed asthma! These fireplaces emit hazardous fumes..

This is an old thread and I wish I had seen it before we built our house in 2019. I tried to persuade our builder that I wanted a vented gas fireplace but he said they only did vent free. Long story short, we’ve never been able to use it because of the terrible, sickening smell (propane). We looked into having it changed to a vented fireplace and that was going to be prohibitively expensive. We ended up buying a Dimplex OptiMyst electric log insert so we could at least have some kind of operational fireplace. It is surprisingly realistic looking; the light looks like fire and the mist looks like smoke. Frankly, it looks more like a wood burning fireplace than our original vent free gas logs did.