Yet another question in my long running series of new house questions. I closed recently on a newly constructed house and in my final walk through with the project manager he demonstrated how the gas fireplace works. When he turned it on a god awful smell started permeating the room, the stench of smoke. The room got a bit cloudy and the smoke alarms in the house went off within minutes.

He said this was perfectly normal and that we just have to run it a little bit every day for a few days and this will go away. I have never had a gas fireplace before so I assumed this break in period was normal.

Fast forward a week later of running it two or three times a day every day and while it has gotten a lot better, it still smells and STILL sets the smoke alarm off. I keep trying to call him to ask him to take a look at it and he is not answering his calls. I have two exotic birds and they are very sensitive to fumes and chemicals, so I am too worried to ever burn my fireplace after I move them into their new home.

Is this normal and is there anything I can do to help break this gas fireplace in a little faster? I have never experienced this in my friends homes that have gas fireplaces.


Fast forward almost a year later... the smell did eventually go away but it took a very long time and constant use. The maintenance checkup from the home builder looked at the fireplace and found that the fireplace was NOT properly sealed by the general contractor! This also explains why when I wasn't using the fireplace that I could feel a bitter cold breeze blowing into my house from the fireplace. The project manager all the while told me this was normal but it was the maintenance sub contractor that told me it was installed incorrectly and he did fix it for me. I haven't had problems since.

  • Is this a gas fireplace that is designed to be vented through a chimney?
    – Pigrew
    Dec 17, 2012 at 5:34
  • 2
    It is possible that a fireplace of this type may have some oil films on the metal left over from the manufacturing process but those should burn off quickly with the first session of use.
    – Michael Karas
    Dec 17, 2012 at 6:59
  • Did the GC leave you a manual for the unit? This is Not normal. Is the unit properly valved for propane or natural gas? Dec 17, 2012 at 21:17
  • All new fireplaces and gas stoves have a thin oil film or protective layer on them to stop rust and protect the metal when in storage. You need to fire it up on full for until the smell goes. We had this problem too and I too thought there was something wrong with it. But after about 30mins that smell and smoke went away.
    – hookenz
    Jul 28, 2013 at 20:59

5 Answers 5


This does NOT sound at all like a normal situation. Either your gas fireplace has a serious flaw or the unit is vented incorrectly. I would stop lighting it and immediately get a professional in to look at it. At the same time you should use every avenue at your disposal to get the builder, contractor, and gas fireplace installer on the hook to look at this unit and replace it if necessary with a properly functioning and correctly installed unit.


I have installed a couple of gas fireplaces. Both came with instructions to operate the fireplace on high for at least five hours in order to off-gas the unit. This should have been done before you moved in. Now you are the canary in the coal mine! As far as the possibility that the unit was installed incorrectly, I am going to reiterate Michael Karas' advice with an addendum:

"At the same time you should use every avenue at your disposal to get the builder, contractor, and gas fireplace installer on the hook to look at this unit and replace it if necessary with a properly functioning and correctly installed unit." This needs to happen now. If the unit is not vented properly you're looking at worse than a bad smell, you're looking at CO poisoning. Which could happen even if the bad smell goes away. Do not operate this unit until you get a professional (preferably 3d party) to look at the fireplace. The real estate agent should be willing to pay the fee.

  • There is no setting to change the heat on it. The PM said that it is VENTLESS but that it draws air from the outside and has a flue for exhaust gases. Which is it because that doesn't make sense? Either way he said he is going to call the fireplace installer and have him come out to take a look at it. Dec 17, 2012 at 14:32
  • I'm guessing that it's thermostatically controlled? There are a number of gas appliances that direct vent to the outside, but that doesn't make them ventless. If it has a flue then the flue is the vent for combustion gases. The termination of this flue needs to be a distinct distance away from any openings into the house - windows, doors, any other apertures. This varies by model and local codes. One recommendation for someone who is obviously as motivated as you are to solve this issue - see if you can download the installation PDF based on a search for the manufacturer and model number.
    – Paul
    Dec 17, 2012 at 14:50
  • Hmph. Ventless with a flue is a contradiction of terms! Unvented gas heating appliances are illegal in residences, at least in any country that has any building code, I should think.
    – bcworkz
    Dec 17, 2012 at 23:47

I installed a new gas Infinite fireplace this week. The tech gave me a operating walk-through, and said to open the windows, place a fan close to it, and run it steady for 5 hours, to burn everything off. Today, it's been running about 2 hours, and the fumes are gone, and the smell is diminishing.


Oh boy ..... We have had the same problem after moving in to our new home 5 years ago. We were told it had to be burned in for 6 - 8 hours to clean off any manufacturing process oils. We have tried this over the years and it has not worked , I took the glass off and there was no sign of this odour inside the fire box. Which makes sense as that should be a sealed unit taking in fresh air and expelling burnt exhaust. But I was checking everything, easiest first....

My new home warranty has expired, and the manufacturer has not responded other then telling me to contact the installed, who has gone out of business. So I'm on my own!!!

Ok so now I had no choice but to rip the mantel off, and the tile surround to gain access to the unit. I was either going to find the problem or it was going in the garbage as there was defiantly an issue with the unit or install. After totally destroying the mantel and tiles, I found the install to be perfect, the builder made a very neat box, the vent was properly installed, so I focused my search to the Majestic gas fireplace unit.

The smell I would get each time we tried it was a chemical smell, very very strong , no smoke, just an odour that after running it for 10 mins would start to take over the house. As I looked over the unit I found all this dried up black sealer everywhere it was crumbling off the unit and a bunch was on the floor. I picked up a piece and wow that's the stink !!! OMG they used the wrong sealer on the fireplace. I say wrong because the sealer required does not smell and does not dry out and crumble off.

On another note the sealer was used to bond the sheet metal seams, the company welded about an inch on each corner and rather then do it right and weld the complete side , they opted to use high heat sealer. In theory this will work but you need the correct sealer.

So after some consideration buy a new unit at 2000 dollars or scrap off the old sealer totally dismantle and then reassemble with proper sealer at 10 dollars, I thought I would give it a go. It took a day of scraping and cleaning to remove the junk that was on the unit.

Last night I reassembled the unit and let it sit over night, this morning I reinstalled the unit and it has been burning for well over 45 mins on hight with a very slight smell probably due to the normal burn in period to cure the sealer.

I'm happy I saved 2000 dollars but it will still cost me 2000 to replace the mantel and tile surround.

This unit was installed in 2008 and this is the first time we could use it....

This is posted on their web site

SPECIAL NOTE TO MAJESTIC CUSTOMERS WITH PRODUCTS MANUFACTURED PRIOR TO JULY 2008: Monessen Hearth Systems Company (MHSC) purchased the Majestic brand from Canadian Fireplace Manufacturers Corp. (CFM) on July 25, 2008. MHSC is not responsible for information about, warranty of nor are we liable for Majestic product manufactured or installed prior to that time. Information regarding those products should be requested from the original seller.

Seeing that this unit was purchased in July of 2008 I couldn't tell you if it is the new company or old that used this toxic sealer. So I suggest stay clear !!!

Hope this helps someone else.....

  • Stories don't make good answers. You should trim this down to get directly to the answer and then provide any additional details to back it up.
    – BMitch
    Jul 28, 2013 at 20:31
  • Great story and a very useful answer. I suspect I may have the same situation (bad sealer).
    – tofutim
    Dec 3, 2014 at 18:17
  • I just looked, and I see black crumbly sealant. :(
    – tofutim
    Dec 3, 2014 at 18:51
  • When you talk about changing out the sealer, are you talking about the black crumbly stuff or did you also do something about the sealant next to the weld?
    – tofutim
    Dec 3, 2014 at 18:52

Our home was built in 2008 with a vented chase mounted gas fireplace. Every time it was lit, that foul, burning wax/gas oven smell filled the room. As with everyone else, we were told to burn it for 40 hours. In ten years, we doubled that, but as of a month ago, the smell was worse than ever. The fireplace was made by Majestic who no longer will service this model, and finding a service company to look at it was impossible. No one wanted to work on the discontinued unit. So I decided to do it myself. First the flues were checked for obstructions with probes and visually. There's a baffle in the burn compartment that can be removed and you can see right through the exhaust pipe. The intake was accesed from outside with wire probes and nothing was found. I next removed most of the volcanic rock from the rear floor of the burn compartment where I found a considerable amount of drywall dust built up in the seams and corners. This was scraped away and vacuumed up. The burner was vacuumed out and any debris removed from around it. After the vacuum, a damp cloth was used to wipe all surfaces. Lots of black crap came up. The exterior of the burn compartment was addressed next. Ours had two five inch round vents in the top, "sealed" off with a square metal door with a half inch of fireproof insulation. Reasoning the insulation didn't make a very tight seal over the holes, the doors were removed and a quarter inch by 6 inch round steel plate was put over each after they were capped with stainless steel foil.

I tried a burn after that but there was still a smell, so the exterior was gone over again with a damp rag, but this time I did the outer sides and back of the heat compartment with a Swifter hand held duster. This allowed me to clean off all the excess drywall dust that had been left by the builder, and after a double cleaning with a damp pad, all that could be done had been done. We lit up and bingo, no smell! That damn dry wall dust on the outside of the burn chamber had been off gassing every time we lit in the past, so if you've tried everything else, clean off that exterior surface of the burn compartment if you can reach it. Now we finally can enjoy our fireplace after 9 years!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.