The three most common reasons why your gas fireplace smells are:
- It is the first use of the season and the fireplace is burning accumulated dust and pet hair – smells like burning dust
- It is a new gas fireplace and it is burning up chemicals from manufacturing – might smell like burning plastic
- You have a gas leak – possible rotten eggs smell
These causes range from totally harmless to extremely dangerous, so it is very important to be able to diagnose the reason why your gas fireplace smells.
Below you can find a list of things that can make your gas fireplace smell, as well as specific smells to look out for and tips for gas fireplace maintenance to prevent unwanted odors.
First Fireplace Use of the Season
Most people don’t use their fireplace during warm seasons. While not in use, it is normal for your gas fireplace to accumulate dust, pet hair, dander, and any other debris. It can even collect this debris if not used for a few weeks.
Then when you turn the fireplace on, it smells like burning dust, burning plastic, and sometimes it even smells like burning wood. These odors are just the smell of the fireplace burning up the common household debris that it collected over the warm months that it went unused.
It should take an hour or less of burning for the bad smells to clear out, and your fireplace will smell normal again.
First Use of a New Gas Fireplace
Don’t be alarmed if your new gas fireplace smells when first turned on. This is a very common occurrence that can make the fireplace have an odor like smoke or burnt plastic.
There are chemicals and paints that are used in the manufacturing of a gas fireplace that burn off when the fireplace is lit for the first time. These odors shouldn’t last for long – one to three hours of burning should do the trick.
New Furniture or Paint Near the Fireplace
If you place a new piece of furniture close to the fireplace, it may heat up and release a chemical-like smell.
The same goes for new paint: if it is close to the fireplace, the fumes from normal off-gassing can smell a lot stronger due to the heat. Most off-gassing from new paint and furniture slows or stops within a few weeks, but you might want to ventilate the room during this time.
Unfortunately, a smell coming from your gas fireplace could mean there is a gas leak, which can cause a house fire or even an explosion. If your fireplace smells like gas, emits a smell like kerosene, or if there is a stink like rotten eggs, evacuate the house and contact your utility company immediately.
A chemical called mercaptan is added to propane and natural gas used for gas fireplaces. It is a harmless chemical, but when burned it smells like sulfur, or rotten eggs. Mercaptan is added so that you can smell when there’s a gas leak, which would otherwise be odorless and undetectable to you.
What about a gas smell from fireplace when off? You might notice a very faint smell of gas even when it is turned off. This should dissipate quickly.
If it doesn’t go away, a gas smell from the fireplace when off could also indicate a gas leak, so it is always better safe than sorry!
If you have any concerns that your gas fireplace could be leaking natural gas, treat it like an emergency even if you’re not sure – call your utility company right away and leave the house until someone can come check it out and give the “all clear.”
Exhaust Leaking from Vent
Another possible cause of your gas fireplace smell is exhaust spilling into the home instead of going up the chimney or flue. This can make the house smell like gas, the same smell that happens if you leave the stove top burner on too long. Some people say it has a smell like candle burning.
The gas burner or gas logs in a vented fireplace produce carbon monoxide just like a wood burning fireplace does, so if you have an exhaust spill it could mean that undetected carbon monoxide is entering the home.
* Be sure to install a carbon monoxide detector near any gas appliance!
Mold or Mildew in Chimney
Are you smelling a damp, musty smell from your fireplace?
Most commonly, this smell comes from the chimney. A ventless gas fireplace likely won’t have this issue because there is no flue or chimney, but a vented fireplace might.
Moisture soaking into the masonry through cracks or pores can cause mildew and mold to develop. To prevent this, experts recommend having professional fireplace maintenance done once a year, ideally at the end of summer when your fireplace has been dormant the longest.
Are fumes from gas fireplace harmful?
They can be very dangerous if they are the result of a gas leak before it is burned or an exhaust leak that contains carbon monoxide.
But “normal” fumes when the unit is new or first turned on are usually not harmful. Open a window or two for fresh air and turn on a bathroom or kitchen exhaust fan until the smell goes away. If it returns, then turn off the fireplace, and call your installer to set up a service call to check it.
Keep a working carbon monoxide detector near the floor close to the fireplace. If it goes off, shut off the fireplace, open doors and a couple windows, and clear the house. Call 911 from outside.