Gas Fireplace

If you’ve looked into vent-free fireplaces at all, you’ve probably discovered there are quite a few differing opinions on the safety of installing one in your home. The basic concept of a vent-free fireplace is easy enough to understand. By burning gas instead of wood, you can create a “smokeless” heat that doesn’t require ventilation and allows all the heat created by the fire to stay in your home. Of course, it’s not exactly that simple. By-products are still created when burning gas in your home, including carbon dioxide, carbon monoxide, sulfur dioxide, among others. These gases get pushed into your home along with the heat, which can create a dangerous situation if not carefully monitored.

Vent-Free Fireplaces and Other Appliances

You might be thinking if all these dangerous gases are being pushed into my home, how is it that vent-free fireplaces are safe at all for residential use? It’s a good question and some people would say they’re not. Others will point out that you’re also openly burning gas when you turn on your stove, and people aren’t exactly showing up in the news condemning the use of gas stove and oven ranges.

Both points of view are valid and misleading. If you have a high capacity oven range, ran all the burners on high for several hours a day (or if it’s malfunctioning), you might have a toxic gas problem. On the other hand, if you properly size a vent-free fireplace and only run it on a limited basis and well within the manufacturer’s specifications, you shouldn’t have any problems with dangerous gases. That said, many homeowners take the stance that no level of dangerous gases are safe in their home.

Carbon Monoxide and Other Dangerous Gases

Of all the dangerous gases, carbon monoxide is the most dangerous and the most notorious. Few homeowners are still unaware of the odorless and colorless gas. It can cause all sorts of health problems ranging from mild headaches to death. If you decide to install a vent-free gas fireplace do yourself favor and install multiple carbon monoxide detectors in your home, including near the fireplace. Check them regularly.

One of the less advertised gases that can be dangerous to your home is water vapor. Excessive water vapor being emitted from your vent-free gas fireplace can cause your wallpaper to peel, as well as other structural damage. Even gases other than carbon monoxide can cause respiratory problems if they’re present in large enough quantities and/or someone in the home has sensitivity to that gas.

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Homeowner Safety and Fireplace Alternatives

Improper installation, improper fireplace sizing, improper use, and appliance failure can all lead to major safety issues. In fact, health concerns over the use of this appliance have led some countries and states within the US to ban vent-free gas fireplaces. Still, too many homeowners covet the low installation and operating cost and only want to use their fireplace on a limited basis. If you’re one of these homeowners, at the very least try to find a contractor/manufacturer who will bear the responsibility for product failure, should something go wrong. Ask these professionals and companies about health concerns. If they dismiss these concerns as foolish myths, you should probably run for the door. On the other hand, if they tell you there are some concerns, but they’ve never had any problems with their fireplaces, ask them to put in writing that they will cover any damages and expenses associated with product failure.

Your best bet remains to simply put up the extra money and install a vented fireplace. It may cost a little more and not be as energy-efficient, but saving a few dollars on your utility bill shouldn’t be as important as the health and safety of your household.


  1. Richard, October 28:

    re: ventless fireplace inserts.
    I have an existing fireplace that i want to convert to an insert. I would like a ventless but have read about the dangers of carbon monoxide etc. would there be an advantage of maybe leaving damper open a little to eliminate the gas leaking into room or should I not worry about it and close dampers fully.


  2. Suzanne Curry, July 11:

    I used my ventless fireplace a lot, I loved it so much.
    But without noticing, I was getting headaches, and listlessness, and finally developed daily debilitating Cluster headaches that damaged my left eye. Diagnosed a year later with Horners Syndrome.
    Haven’t used the fireplace since. Be careful what you wish for. It costed over $4,000 to install and purchase. 🙁

  3. Mel Arnott, October 14:

    I know I have a U.K. email address but I actually live in the USA. We are having a ventless gas fireplace inserted and after reading the dangers that can occur we have now opened up our chimney. The chimney is over 100 years old and built to house a coal fire so it is quite narrow.
    Even though it is narrow will this make it safe to have the ventless fireplace installed or should we put doors on the front as well.
    Any advice is very much appreciated. Thank you. Melanie

  4. Shirley Roberts, January 16:

    How to vent a ventless gas fireplace

  5. phil hersey, January 18:

    I have heated my 2500sf victorian in carson city nevada for over 15yrs using only 5 ventless gas logs/stoves. It’s dry in Nevada in winter so the moisture they put into room feels good and doesn’t condense on the single pane glass after i put in storm windows. My CO detectors have NEVER measured ANY CO. If the flame is allowed to touch something like a fake log, this can cause a tiny amount of white soot to expell- not sure if this is a health concern or not but we love heating this way.

  6. Sarah elliott, January 21:

    My ventless fireplace has put black suit all over the ceiling and furniture! Does this mean that we are breathing In this suit? Cleaned the room yesterday and everything was covered with black dust! I
    Am concerned because of previous cancer and we use this fireplace a lot due to the cold cold weather!

  7. Moe Hufsey, February 2:

    Can a gas fireplace be used on an inside wall or does it need a chimney type setup

  8. Larry ray, February 4:

    Is it okay to cap off a flume when installing vent less logs? Do you still need ventilation

  9. Rich, March 18:

    Sarah Elliott.
    There’s basically 4 reasons a vent-free gas fireplace will produce soot like you described.

    1. The unit hasn’t been serviced annually since you purchased it.
    Vent-fee gas logs are not maintenance free. They must be inspected & cleaned
    annually by a professional gas technician.

    2. The log(s) are out of place and are impinging the flames.
    This is one of the most common problems. Check your Owners Manual for the proper
    3. You’re running a ceiling fan in the wrong direction and/or at to high a speed.
    Using a ceiling fan to help distribute the heat works well. But, the blades of the fan
    should be set to turn counter clock (as you’re looking up at the fan) and set on slowest
    4. You’re burning scented candles while the burner is in operation.
    Scented candles soot any way. When you add the warm, moist heat from the Vent-free
    Gas Log Set. They’ll soot 50 times worse.

  10. Rich, March 18:

    Mel Arnott

    I know this is a little late. But, what you’re doing is creating a Vented gas fireplace. If you only want the ambience of a fire and not interested in the heating capability. That’s what you have created.

  11. Rich, March 18:

    Larry ray.

    It’s not necessary to cap of the “flue” unless you want to. Having a screened Chimney Cap to keep the birds and squirrels out is a better idea. Closing the damper is all you need to do.

  12. Rich, March 18:

    Mel Arnott

    One more thing Melanie . Glass doors and Vent-free gas log sets don’t work well together. Even if you leave them open while the log set is in operation. A freestanding trifold hearth screen works well. The firebox opening should remain just that … Open.

  13. Rich, March 18:

    Moe Hufsey.
    Yes. If you’re installing a Vent-free Gas Fireplace. Make sure that the maximum BTU Output is not more than you need or can handle.

  14. Rich, March 18:

    To ALL.
    Vent-free gas log sets and fireplaces are totally safe. Despite what some dealers and websites will tell you. They just want to sell you something that’s more expensive and inefficient. The Dept of Energy rates a Vented Log Set or Fireplace as Decorative Gas Appliance. Vent-free is rated as a Decorative Supplemental Gas Heating Appliance.

    I have been in the gas fireplace business for almost 20 years and have found that 95% of the problems customers complain about are due to operator error. The rest are normally covered by the manufacturer’s warrant.

    My best advice is make your purchase from a brick and mortar hearth dealer. One that will come to your home and survey what you want to do. Check their Customer Comments & Reviews about their work and knowledge. Different states have different Codes. It’s not one size fits all.

    And finally, Don’t buy online or from a Big Box Store, just because the price is cheaper. 9 times out of 10 you’re buying a piece of junk that has a very limited warranty and is only a seasonal product for them.Plus, who’s going to install it properly for you?

    Vent-free gas heating appliances do require annual service. Not doing this will cause problems down the road, that you don’t want to have to deal with.

    Also, keep in mind there are two types of Vent-free Gas Log Sets and Fireplaces. Ones for Natural Gas and the other for Propane Gas. They can not be converted from one gas type to the other. In addition there are 2 types of logs. Ceramic Fiber and Refractory Concrete.
    Ceramic Fiber feels like a piece of Styrofoam when you pick one up and do not last long when burning Propane.
    Refractory Concrete are just that. A Molded Refractory Concrete Log is fired under high heat and will last forever on either Natural Gas or Propane.

    Hope all of this helps you make the right decision.

  15. Sharon Howell, July 27:

    We bought a home in Evans, GA in 2010. Our fireplace was ventless gas. But, 2 years ago 2016), our son, who is a builder (in a diiferent state), spent the night. We had the fireplace on as we had morning coffee. Our son got up an hour later and told us to turn it off. He had a meter to measure the carbon monoxide levels (and yes we have 3 that came with the NEW house but they didn’t go off.) Anyway, his registered dangerous levels. So, we had it completely disconnected Now we have an electric fireplace. Love it and I don’t have to worry about dying in my sleep. Why are ventless fireplaces not banned?

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