Skip to Content

Are Ventless Gas Fireplaces Legal in Canada?

In many parts of the world, people use the technology of ventless gas fireplaces. I, in fact, nearly helped my good friend install one in his cabin two years ago. In my friend’s mind, the biggest attraction to the ventless fireplace was the inexpensiveness. They are usually cheaper and less of a hassle to install than vented types as you don’t need to worry about a flue. So, this was his plan…until he checked his local building code.

Ventless gas fireplaces are prohibited by code in Canada and other parts of the world due to the obvious safety issues associated with them. Here, I provide you with the codes in question, details regarding the health and safety risks of ventless gas fireplaces, as well as the reasoning behind their invention.

Ventless gas fireplaces are illegal because they are against the National Building Code of Canada, namely, Section (2). This code is adopted by many jurisdictions, making its provisions law. These fireplaces release hazardous chemicals directly into a home. Fines, not prison, are the likely penalty for installing one.

Ventless Gas Fireplaces Are Prohibited by Codes

The National Building Code of Canada, cited from Section, point 2 (page 975), states:

“Natural gas and propane fireplaces shall be

a) direct-vent (sealed), and
b) pilot-on-demand, interrupted, or intermittent ignition systems without a standing pilot light.”

This means that you cannot have an unsealed gas fireplace, i.e., one that opens into the room, which a ventless gas fireplace is by nature (it cannot be sealed because it has no flue to take in oxygen and dispel combustion gases).

Installing a ventless gas fireplace would constitute a violation of the National Building Code.

Are Codes the Law?

The National Building Code itself is what is known as a model building code. Its provisions are not legal requirements until it has been adopted by a particular jurisdiction. However, most provinces in Canada have adopted the National Building Code.

You can check your own jurisdiction, but the likelihood is that they have adopted this code, making violations of the regulations therein an illegal act. As such, because ventless gas fireplaces do not fulfill the requirements of the National Building Code of Canada, they are considered to be illegal. 

Pleasant Hearth 42 in. Radiant Zero Clearance Universal Vent Free firebox, Black - PHZC42F

However, if you install a gas fireplace, you will not go to prison, nor are you likely to receive any kind of mark on your permanent record. The most reasonably practicable way to deal with the non-code compliant installation of ventless gas fireplaces is with a fine or multiple fines.

Prohibition Supported by Other Regulations

Section of the National Building Code of Canada is not the only place you can see Canada’s prohibition of ventless gas fireplaces by codes.

In the Guide to Canada’s Energy Efficiency Regulations, it can be seen that gas fireplaces must be vented by way of natural venting (chimneys), direct venting (sealed), or powered venting.

Why Ventless Gas Fireplaces Are Prohibited

Ventless gas fireplaces, while in theory may seem like a great idea, in practice they can be extremely dangerous and even deadly. This is due to the release of combustion gases directly into the living space.

Such gases released from fireplaces have led to hospitalization and even death in some cases. Therefore, the Canadian government, along with many others, have prohibited these fireplaces in an attempt to protect the public. 

Release of Combustion Gases

Traditional fireplaces are equipped with a venting flue to ensure the release of combustion gases safely away from a dwelling’s inhabitants. Ventless gas fireplaces, however, are unable to do the same due to their lack of a flue.

So, where do these gases go then? Ventless gas fireplaces push all unburned gases such as carbon monoxide and water vapor into the building in which they are fixed.

While the emission levels of these gases differ depending on a lot of factors, they are still much higher than that of a traditional fireplace under normal circumstances, let alone in the event of a faulty fireplace. 

In the event of fireplace functional issues, unlike a traditional fireplace where you simply would ensure that the flue is open and all is well, ventless fireplaces can become dangerous—and quickly. 

Effects of Combustion Gases on People and Animals

As mentioned above, carbon monoxide and water vapor are released into one’s house when they have a ventless fireplace installed. Both carbon monoxide (directly) and excess water vapor (indirectly) are very harmful and even deadly to humans and animals alike. 

Most Common Causes of CO Poisoning in the US
Most Common Causes of CO Poisoning in the US

Water Vapor

Water vapor, while it seems harmless enough, is not something you want to be pumped into your living room. While the ventless gas fireplace is in use, the room will start getting moist and muggy, like a poorly ventilated bathroom after a long, hot shower.

While this may not seem like a very bad thing, over time, the constant humidity will become the perfect breeding ground for mold. In fact, moist and hot air is considered to be damaging enough to home and health for the International Residential Code to strictly prohibit venting bathroom fans into any room or space in a house.

Mold, while a gross sight to see in a living room, is not just an eyesore.

Once the mold starts releasing spores into the air, those susceptible and allergic will start becoming extremely ill, which may even lead to hospitalization. Moreover, pets, unless closely supervised, may also eat the mold, causing them to become severely ill and potentially die. 

Carbon Monoxide

Carbon monoxide (CO), nicknamed the “silent killer,” is something you do not want lurking around your house. According to the CDC, in the USA, at least 430 people die annually from CO poisoning.

Reportedly, 34% of these CO-related deaths come from heating systems, which includes ventless gas fireplaces.

illustration of Symptoms of Carbon Monoxide Poisoning

While many people are able to escape from carbon monoxide poisoning, the first to perish are children and animals, so it’s best to avoid any possibility of this happening in your home.

Please visit the CDC website for more information on prevention. 

If there is any type of fuel-burning appliance in the home a Carbon monoxide detector is a must. It is cheap insurance against the silent killer.

Kidde Carbon Monoxide Detector, Plug In Wall with AA Battery Backup, Test-Hush Button
  • Easy Installation - simply plug-in to a standard, 120V outlet in your home
  • 2-AA battery backup provides protection during a power outage
  • 85-decibel alarm announces when carbon monoxide is detected
  • Peak Level Memory records the last time carbon monoxide was detected or when the unit was last tested

Last update on 2024-05-29 / Affiliate links / Images from Amazon Product Advertising API

Why Do Ventless Gas Fireplaces Exist?

With all of the dangers caused by ventless gas fireplaces, why were they created in the first place?

Well, these ventless gas fireplaces burn propane gas, which fuels them at near 100% efficiency, greatly reducing the volume of harmful gases released into the atmosphere

Ventless gas fireplaces were also produced to allow for people to have fireplaces in homes where they architecturally cannot construct a flue. They can be installed almost anywhere, making them much cheaper and more widely available. 

You will not struggle with cold drafts coming through the fireplace when it is not in use if the gas fireplace is not vented to the outside.

HOMCOM Wall-Mounted Stainless Steel Ventless Ethanol Fireplace Heater with Tempered Glass for Living Room, Black

In order to mitigate safety risks caused by ventless gas fireplaces, many manufacturers install an oxygen-detection sensor, which will automatically turn off the fireplace if the oxygen levels in the surrounding areas become dangerously low. A carbon monoxide detector is also a must for any fuel-burning appliance.

The manufacturers also recommend opening a window while using these fireplaces in order to prevent any possible carbon monoxide build-ups. However, this recommendation is unlikely to be followed because it negates the purpose of the heater itself. 

Gas Fireplace | Does It Need Makeup Air?


Amazon and the Amazon logo are trademarks of, Inc, or its affiliates.