Carbon Monoxide Detectors FAQs

Carbon monoxide (CO) is a colourless, odourless, and tasteless gas produced by burning fuels such as natural gas, propane, wood, charcoal, and gasoline. Because it is undetectable without a dedicated device, carbon monoxide is often called the “silent killer.” Exposure can happen quickly and without warning, especially in enclosed or poorly ventilated spaces. Carbon monoxide detectors work by sensing the presence of CO gas in the air, and they trigger an alarm when dangerous levels are detected. These devices continuously monitor air quality to alert occupants before CO concentrations become harmful.

Every household or business with fuel-burning appliances, fireplaces, or garages should have at least one carbon monoxide detector. It’s not just homeowners who need protection—landlords, business owners, and property managers are also responsible for carbon monoxide safety.

Carbon monoxide is commonly found near malfunctioning fuel-burning equipment. It can build up indoors when exhaust gases are not vented properly or when appliances are used in enclosed spaces. Sources include:

• Gas furnaces and water heaters
• Wood-burning fireplaces and stoves
• Gas stoves and ovens
• Portable generators and heaters
• Vehicles idling in attached garages

Symptoms of CO poisoning can be subtle and are often mistaken for the flu or fatigue. The longer the exposure, the more serious the symptoms become. Look out for headache, dizziness, nausea, confusion, chest pain, and loss of consciousness.

If your carbon monoxide detector goes off, take the alarm seriously. Evacuate everyone from the building immediately, including pets. Once outside, call emergency services. Do not re-enter the building until it has been inspected and cleared. For safety, remember what to do if a carbon monoxide detector goes off:

• Leave the building quickly.
• Call 911 from outside or a neighbor’s home.
• Wait for professional clearance before returning.
• Have the source of CO professionally inspected.

Carbon monoxide alarms are not designed to detect explosive gases like natural gas or propane. These alarms detect only carbon monoxide. To monitor gas leaks, you will need a separate explosive gas detector. Some combination units may include both functions, but it's important to confirm the specifications of your device.

Knowing where to place carbon monoxide detector units is important, but it’s equally important to avoid improper placement. Detectors should not be installed in areas that could result in false alarms or missed detection. Avoid placing detectors:

• Directly above fuel-burning appliances
• In bathrooms or humid areas
• Near open windows or vents
• In direct sunlight
• Too close to ceiling fans or ducts

Battery life varies depending on the model. Most battery-operated carbon monoxide detectors last 5 to 10 years, but the batteries themselves may need replacing annually or as indicated by the manufacturer. Many alarms will chirp to alert you when the battery is low or when the device is at the end of its service life.

You can replace a standalone smoke detector with a smoke and carbon monoxide detector for dual protection. However, do not replace smoke detectors with carbon monoxide-only devices, as this removes fire protection. If space is limited, consider a combination unit that meets both fire and carbon monoxide detection standards.

Testing your carbon monoxide detector is simple and should be done monthly. Most units have a test button you can press and hold until you hear a beep. This checks the circuitry and battery, but does not verify sensor accuracy. For full testing, you may need to consult the manufacturer’s instructions or schedule a professional inspection.

The answer depends on the device model. A flashing red light may indicate a low battery, active alarm, or end-of-life warning. Some models flash red during normal operation. Always refer to the device manual to interpret flashing patterns correctly.