Carbon Monoxide Safety Ottawa: Protecting Your Family at Home
Carbon monoxide kills Canadians every year — and the majority of CO-related injuries and deaths happen inside the home. It’s colourless, odourless, and tasteless. You can’t see it, smell it, or taste it. By the time you feel symptoms, you may already be in serious danger.
Every Ottawa home with a gas furnace, water heater, gas fireplace, gas stove, or attached garage produces potential carbon monoxide sources. When these appliances work correctly and vent properly, CO exits safely. When something goes wrong — a cracked heat exchanger, a blocked vent, backdrafting — CO enters your living space invisibly.
This guide covers where carbon monoxide comes from in Ottawa homes, the new Ontario alarm requirements that took effect in 2026, what CO poisoning looks like, and the HVAC maintenance that prevents CO problems in the first place.
At Gas Man Ottawa, we install carbon monoxide detectors, perform gas safety inspections, and maintain every gas appliance in your home to keep your family safe. Call (613) 880-3888.
Where Does Carbon Monoxide Come From in Your Home?
Carbon monoxide is produced whenever fuel burns incompletely. In an Ottawa home, the most common CO sources are:
Gas Furnace
Your furnace is the single largest combustion appliance in most Ottawa homes, and it runs for six months of the year. The heat exchanger separates combustion gases from the air circulating through your home. A cracked or corroded heat exchanger — which becomes more likely as the furnace ages past 15 years — allows CO to leak directly into your ductwork and be distributed to every room in the house. Other furnace-related CO risks include blocked exhaust vents (snow, ice, debris, bird nests), malfunctioning burners producing incomplete combustion, and damaged or disconnected flue pipes on older standard-efficiency furnaces.
Water Heater
Gas water heaters and tankless water heaters produce combustion gases every time they heat water. Conventional tank water heaters with atmospheric venting (the ones with a metal flue pipe rising from the top) are particularly susceptible to backdrafting — a condition where exhaust gases are pulled back into the home instead of rising up and out through the chimney. Backdrafting commonly happens when bathroom exhaust fans, kitchen range hoods, or clothes dryers create negative pressure inside the home.
Gas Fireplace
A gas fireplace produces CO during operation. Direct-vent fireplaces are sealed systems that draw combustion air from outside and exhaust gases back outside — they’re the safest configuration. But natural-vent (B-vent) fireplaces and ventless (vent-free) models rely on room air for combustion and can contribute to indoor CO levels if the room isn’t adequately ventilated or if the fireplace malfunctions.
Gas Stove and Oven
A gas stove produces low levels of CO during normal use. Using the oven to heat your home — which some people resort to during power outages or furnace failures — produces dangerous CO concentrations because the oven isn’t designed for continuous, unvented operation. Always use your kitchen exhaust fan when cooking with gas.
Attached Garage
A running vehicle in an attached garage is one of the most common causes of fatal CO poisoning in homes. Even with the garage door open, CO can accumulate and migrate into the living space through shared walls, doorways, and ductwork. Never warm up your car in an attached garage.
Generators
Portable generators produce massive amounts of CO. During Ottawa power outages (like the 2022 derecho and 2023 ice storm), generator-related CO poisonings spike because people run generators inside garages, basements, or too close to windows and doors. A natural gas standby generator installed permanently outside the home eliminates this risk entirely.
Ontario’s Carbon Monoxide Alarm Law — Updated for 2026
Ontario has some of the strongest carbon monoxide alarm requirements in Canada. As of January 1, 2026, the Ontario Fire Code expanded these requirements to provide even more protection.
Who Needs CO Alarms?
CO alarms are legally required in any Ontario home that has a fuel-burning appliance (gas furnace, water heater, boiler, gas stove, gas dryer, etc.), a fireplace (gas or wood-burning), an attached garage or carport, or receives heated air from a fuel-burning appliance located outside the dwelling (such as a shared utility room in a condo building). This applies to detached houses, townhouses, condos, and apartments.
Where Must CO Alarms Be Installed?
Under the updated rules effective January 1, 2026, CO alarms are required adjacent to each sleeping area (in the hallway or area immediately outside bedrooms) and on every storey of the home — including floors that don’t have bedrooms. The “every storey” requirement is the major change that caught many homeowners off guard. Previously, CO alarms were only required near sleeping areas. Now, a typical two-storey Ottawa home with a basement needs a minimum of three CO alarms — one on each level.
Alarm Types and Standards
CO alarms can be battery-operated, plug-in, or hardwired. Combination smoke/CO alarms are available and satisfy both requirements in one device. All CO alarms must be certified to Canadian standards (look for the CSA or ULC logo). CO alarms must be replaced every 7–10 years (check the manufacturer’s date on the unit). Batteries should be replaced at least once per year. Test the alarm monthly by pressing the test button.
Penalties
Failure to comply with Ontario’s CO alarm requirements can result in fines of up to $50,000 for individuals and up to $100,000 for corporations. More importantly, non-compliance puts your family at risk from a hazard that’s entirely preventable.
Gas Man Ottawa can install and test carbon monoxide detectors throughout your home to ensure full compliance with the updated law. Call (613) 880-3888.
Signs of Carbon Monoxide Exposure
CO poisoning symptoms mimic common illnesses, which is why it’s so frequently misdiagnosed. The key indicator is that multiple family members develop similar symptoms simultaneously, and symptoms improve when they leave the house.
Low-Level Exposure
Headache (the most common early symptom), dizziness, nausea, fatigue, and confusion. These symptoms resemble the flu — without the fever. If you notice these symptoms during the heating season and they seem to come and go, especially when you’re home, consider CO exposure as a possible cause.
Moderate Exposure
Severe headache, drowsiness, disorientation, vomiting, rapid heart rate, and impaired judgment. At this level, your ability to recognize the danger and take action is compromised — which is what makes CO so deadly.
High-Level Exposure
Loss of consciousness, seizures, and death. High CO concentrations can incapacitate a person within minutes. Sleeping occupants are particularly vulnerable because they can transition from low-level to lethal exposure without ever waking.
What to Do If Your CO Alarm Sounds
Do not ignore a carbon monoxide alarm. Take it seriously every time. Get everyone out of the house immediately — including pets. Call 911 from outside the home. Do not go back inside until emergency services confirm the home is safe. If anyone shows symptoms of CO poisoning, tell the paramedics — they need to know. Once the immediate emergency is cleared, call (613) 880-3888 or your HVAC contractor to inspect every gas appliance, flue, and vent in the home before reoccupying.
How HVAC Maintenance Prevents Carbon Monoxide Problems
The vast majority of residential CO incidents are caused by HVAC equipment that isn’t functioning properly — and most of those malfunctions are detectable during routine annual maintenance. Here’s how each maintenance task protects against CO:
Heat Exchanger Inspection
The heat exchanger is the critical safety barrier in your furnace. During annual furnace maintenance, the technician visually inspects the heat exchanger for cracks, corrosion, and deterioration. A cracked heat exchanger is the most serious CO hazard in a home — it allows combustion gases to leak directly into the air your family breathes. If a crack is found, the furnace is “red-tagged” and shut down until repaired or replaced.
Combustion Analysis
A technician uses a combustion analyzer to measure CO levels in the furnace flue gases. Normal CO levels are below 100 ppm in the flue. Elevated CO in the flue indicates incomplete combustion — dirty burners, incorrect gas pressure, or insufficient combustion air. Catching these issues during a tune-up prevents them from escalating to dangerous levels.
Venting Inspection
The technician inspects the entire venting path from the furnace to the exterior — checking for disconnections, corrosion, improper slope, blockages, and signs of condensation damage. A blocked or disconnected vent is a direct path for CO to enter your home. This inspection also covers the water heater flue, gas fireplace venting, and any other fuel-burning appliance exhaust paths.
Gas Leak Detection
Using a combustible gas leak detector, the technician scans all gas connections — at the gas piping, appliance connections, gas valves, and fittings — for leaks. While a gas leak is a fire/explosion hazard rather than a direct CO hazard, the inspection is part of a comprehensive gas safety check that protects your home from all combustion-related risks.
Appliance-Specific Maintenance
Each gas appliance in your home should be inspected annually: your furnace, water heater, gas fireplace, boiler, and any other gas-fired equipment. Each has its own potential failure points that can produce CO — and each is covered during a Gas Man Ottawa maintenance visit.
Ottawa-Specific CO Risks
Ottawa’s climate and housing stock create several CO risk factors that homeowners should be aware of:
Snow-Blocked Furnace Vents
High-efficiency furnaces exhaust through PVC pipes that exit one to two feet off the ground on the exterior wall. Heavy Ottawa snowfall — especially during February and March — can bury these pipes, blocking exhaust and forcing combustion gases back into the home. Add vent clearing to your snow removal routine. After every major snowfall, check that both the intake and exhaust pipes are clear.
Extended Heating Season
Ottawa’s six-month heating season (November through April) means your furnace runs thousands of hours per year. More operating hours mean more wear on the heat exchanger, burners, and venting components — and more opportunity for problems to develop. Annual maintenance before each heating season catches issues before they become hazards.
Older Home Heating Systems
Many Ottawa homes have furnaces and water heaters that are 15–25 years old. Older furnaces with aging heat exchangers and older water heaters with atmospheric venting are the highest-risk appliances for CO. If your furnace is over 15 years old, annual heat exchanger inspection becomes especially critical. If your water heater uses a metal flue pipe into a chimney (rather than sealed PVC venting), backdrafting risk is higher.
Power Outage Generator Use
Ottawa experiences significant ice storms and summer derechos. During extended power outages, portable generators cause a surge in CO emergencies. Never run a portable generator inside your home, garage, or any enclosed or partially enclosed space. Keep generators at least 6 metres from any window, door, or vent. Consider a permanently installed natural gas standby generator — it’s installed outside, vented properly, and starts automatically during outages with no CO risk to your home’s interior.
Carbon Monoxide Prevention Checklist
| Action | Frequency | Who |
|---|---|---|
| Test CO alarms (press test button) | Monthly | Homeowner |
| Replace CO alarm batteries | Annually | Homeowner |
| Replace CO alarms | Every 7–10 years | Homeowner / Gas Man |
| Check furnace intake/exhaust vents for blockage | After every major snowfall | Homeowner |
| Schedule furnace maintenance | Annually (fall) | Gas Man Ottawa |
| Schedule water heater maintenance | Annually | Gas Man Ottawa |
| Schedule gas fireplace maintenance | Annually (fall) | Gas Man Ottawa |
| Full gas safety inspection | Annually or when buying a home | Gas Man Ottawa |
| Inspect visible flue pipes for rust, disconnection | Annually | Homeowner (visual) / Pro (detailed) |
| Use kitchen exhaust fan when cooking with gas | Every time | Homeowner |
| Never warm up car in attached garage | Always | Homeowner |
| Never run generators indoors or in garage | Always | Homeowner |
Frequently Asked Questions: Carbon Monoxide Safety
How many carbon monoxide detectors do I need in my Ottawa home?
Under Ontario’s updated fire code (effective January 1, 2026), you need a carbon monoxide alarm adjacent to each sleeping area and on every storey of your home. A typical two-storey Ottawa home with a basement needs a minimum of three CO alarms. Gas Man Ottawa can install CO detectors in compliance with the current law. Call (613) 880-3888.
What causes carbon monoxide in a house?
Any fuel-burning appliance can produce CO — your furnace, water heater, gas fireplace, gas stove, and even a car in an attached garage. CO enters your living space when these appliances malfunction (cracked heat exchanger, dirty burners), when venting is blocked or disconnected, or when fuel-burning equipment is used improperly (running a generator indoors, heating with an oven).
What should I do if my carbon monoxide alarm goes off?
Get everyone out of the house immediately. Call 911 from outside. Do not go back inside until emergency services confirm it’s safe. Then call your HVAC contractor to inspect all gas appliances before reoccupying. Never assume a CO alarm is malfunctioning — treat every alarm as real until proven otherwise.
Can I smell carbon monoxide?
No. Carbon monoxide is completely odourless, colourless, and tasteless. You cannot detect it with any human sense. The only way to know CO is present is a working CO alarm. This is why proper alarms and annual HVAC maintenance are both essential — alarms detect the problem; maintenance prevents it.
How often should I replace my carbon monoxide detector?
Every 7–10 years, depending on the manufacturer’s specifications — check the date printed on the unit. CO alarm sensors degrade over time and become unreliable, even if the alarm still “tests” properly when you press the button. Replace batteries annually and test the alarm monthly. If your alarm is chirping intermittently, it may need new batteries or it has reached end of life and needs replacement.
Does annual furnace maintenance really prevent CO problems?
Yes. The majority of residential CO incidents involve furnaces with cracked heat exchangers, blocked venting, or malfunctioning burners — all of which are detectable during routine furnace maintenance. A technician’s combustion analysis, heat exchanger inspection, and venting check are your primary line of defence against CO. Your CO alarm is the backup that catches what maintenance misses — not the other way around.
Is natural gas the same as carbon monoxide?
No. Natural gas (methane) and carbon monoxide are completely different. Natural gas has an added odourant (mercaptan) that smells like rotten eggs — you can detect a gas leak by smell. CO is odourless. A CO alarm does not detect gas leaks, and a gas leak detector does not detect CO. Your home needs both: CO alarms on every level and a gas safety inspection to check for gas leaks at all connections.
When should I get a gas safety inspection?
Get a gas safety inspection annually as part of your HVAC maintenance routine, when buying or selling a home, if you suspect a gas leak (rotten egg smell), if your CO alarm has sounded, or if you notice any signs of combustion problems (yellow furnace flame, soot around vents, persistent headaches during heating season). Gas Man Ottawa is TSSA-registered and performs comprehensive gas inspections that cover every appliance and gas line in your home.
Keep Your Family Safe — Call Gas Man Ottawa
Carbon monoxide safety isn’t optional — it’s the most important responsibility you have as a homeowner with gas appliances. The combination of working CO alarms, annual HVAC maintenance, and regular gas safety inspections provides three layers of protection for your family.
Gas Man Ottawa is TSSA-registered and serves homeowners across Central Ottawa, Kanata, Orleans, Barrhaven, Nepean, Manotick, and Gloucester.
Call (613) 880-3888 or contact us online to schedule a gas safety inspection, CO detector installation, or annual maintenance. Check our customer reviews and our service guarantee.
Your family’s safety starts with the air they breathe. Make sure it’s clean and safe.