Reducing The Risks of Carbon Monoxide Buildup This Winter
While winter brings cozy nights and the beauty of falling snow, it also introduces new risks, like carbon monoxide (CO) buildup in your home.
The risk of carbon monoxide poisoning is significantly heightened in the winter months, not only because homes are sealed tightly to retain heat, but also due to the increased, long-term use of central heating systems, the potential for blocked vents and flues, and the unsafe operation of auxiliary heating sources and generators during severe weather.
What is carbon monoxide?
Carbon monoxide is a byproduct of incomplete combustion. Fuel-burning appliances like furnaces, dryers, water heaters, and fireplaces release gases that are normally vented outside. If vents become blocked or obstructed, these harmful gases can accumulate inside your home.
Why is carbon monoxide so dangerous?
Carbon monoxide, known as the ‘silent killer, is an odorless, colourless gas that can cause dizziness, headaches, nausea, confusion, and, in severe cases, death. It displaces oxygen in your blood, leading to suffocation and organ damage.
How winter raises the risk
1. Increased Use of Fuel-Burning Appliances
Colder weather means people rely more heavily and frequently on appliances that produce CO as a byproduct of burning fuel (like natural gas, propane, oil, wood, or kerosene).
Furnaces and Heating Systems: These run for longer periods. If a furnace is not properly maintained or has a cracked heat exchanger, it can leak CO into the home's air circulation system.
Fireplaces and Wood Stoves: Increased use of these devices, especially with an improperly opened or dirty flue, can lead to CO buildup indoors.
Malfunction or Wear: Any fuel-burning appliance—including water heaters, gas stoves, and clothes dryers—that is old, malfunctioning, or not regularly serviced by a qualified technician is more likely to burn fuel incompletely and produce dangerous levels of CO.
2. Improper Use of Auxiliary/Backup Heating Sources
When the primary heating system fails or during a power outage, people often resort to unsafe methods of supplemental heat.
Generators: Portable generators, used during storms and power outages, are a leading cause of fatal CO poisoning when they are operated inside a garage, basement, shed, or too close to a house (near a door, window, or vent). They must always be used outside and at least 20 feet away from the structure.
Outdoor Appliances Indoors: Bringing outdoor-only devices inside, such as charcoal grills, hibachis, or propane heaters/stoves intended for camping, is extremely dangerous as they are not vented for indoor use and quickly fill an enclosed space with lethal CO.
Using Gas Ovens/Stoves for Heat: Using a gas range or oven as a source of home heat is highly risky and can lead to a deadly accumulation of CO.
3. Vehicle Exhaust
Warming Up Cars: Idling a car in an attached garage—even for a short time or with the garage door open—allows CO to seep into the home.
Snow-Blocked Tailpipes: If a car is running while stuck in snow, and the exhaust pipe gets blocked by a snowbank, CO can be forced back into the car's cabin, quickly causing poisoning.
How to keep your family safe
The Ontario Fire Code requires CO alarms in all homes with fuel-burning appliances, fireplaces, or attached garages, regardless of the building’s age. To ensure they’re working effectively:
Test your CO alarms at least once a month
Replace batteries at least once a year, or when the low-battery signal sounds.
Keep vents and chimneys clear of snow, ice, and debris.
Keeping it all up to code
Not sure if your home or building is fully compliant and ready to protect your occupants? The CodeNext team ensures compliance with both Building and Fire Codes for new and existing properties. Explore our services today to learn more about how we can keep your buildings and your loved ones safe this winter.