Smoke & Carbon Monoxide Detectors: What to Look For & When to Replace

Keeping your home and family safe starts with reliable smoke and carbon monoxide detection. At Blais Electric, we help homeowners across Guelph, Kitchener, Waterloo, and Cambridge stay protected with professional smoke alarm installation, inspection, and replacement services. Whether your alarms are due for replacement or you are unsure if they are working properly, our ESA-licensed electricians can ensure your system meets Ontario Fire Code and Canadian Electrical Code standards.

A translucent house model and a smoke detector are depicted in a haze, symbolizing home safety and the importance of fire prevention measures.

Why Smoke Alarm Maintenance Matters
Smoke and carbon monoxide alarms are your first line of defence in the event of a fire or gas leak. These life-saving devices provide early warning so you can evacuate safely. Unfortunately, many Ontario homes still have outdated or improperly installed detectors that may not function when needed most.

Regular maintenance and timely replacement are essential for reliable performance. According to Ontario fire safety regulations, working smoke alarms are required on every storey of your home and outside all sleeping areas. Homes that also include fuel-burning appliances or attached garages must have carbon monoxide alarms as well.

How to Know When It’s Time to Replace Your Smoke or Carbon Monoxide Detectors

1. Inspect the Colour and Condition of Your Detectors

If your smoke alarm or carbon monoxide detector looks yellowed, discoloured, or shows physical signs of aging, it is time to replace it. Plastic housings naturally change colour over time due to heat and airborne particles, and this often signals that the unit’s internal sensors are no longer reliable.

2. Replace Batteries Annually

Even if your alarms look fine, fresh batteries are a must. Most smoke and carbon monoxide detectors will chirp or beep when the battery is low, but it is a good habit to replace all batteries once a year. After changing the batteries, always press the test button to make sure the alarm is working.

You can also use an aerosol smoke detector test spray to confirm that the unit responds correctly. These test sprays are available at most hardware stores throughout Guelph and the Tri-Cities.

3. Nuance Tripping

Let us guess. It won’t stop chirping. This is the number one reason people call us. When alarms sound randomly or seem to go off without cause, it often points to a faulty unit, expired sensor, or loss of power to the hardwired system—leaving it to run on battery only. Even if you replace the batteries, if the chirping continues, it’s a sign the detector needs replacing.

4. Replace All Detectors Every 10 Years

The National Fire Protection Association (NFPA) and the Ontario Fire Code recommend replacing all smoke and carbon monoxide detectors at least every ten years, even if they appear to work properly. Over time, sensors lose accuracy and response speed, which can delay warning times during an emergency.

If you are unsure how old your detectors are, check the manufacture date printed on the back of each unit. If the date is missing or older than ten years, it is safest to have them replaced immediately. While some detectors chirp when they’ve expired, others don’t—so relying on the sound alone isn’t enough to know when it’s time for a replacement.

Professional Installation for Maximum Protection

While many homeowners replace smoke alarms themselves, working with a qualified electrician ensures that your detectors are properly wired, interconnected, and positioned for full coverage. Improper installation can result in false alarms or areas of the home left unprotected.

At Blais Electric, our team provides complete smoke and carbon monoxide detector installation for both hardwired and battery-operated systems. We follow all ESA guidelines to ensure your alarms are installed correctly, interconnected where required, and compliant with Ontario Fire Code standards.

New electrical code requires smoke and carbon monoxide detectors to be hardwired and interconnected, so if one alarm goes off, they all do. Older systems are often grandfathered in, meaning they don’t need to be hardwired—but their batteries must be replaced every year to ensure they continue to provide proper protection. Even these older battery-operated detectors still have an expiration date and should be replaced every ten years.

A person is installing a white smoke detector on a textured ceiling, using both hands to secure the device in place.

Tips for Homeowners in Guelph and the Tri-Cities

Install at least one smoke alarm on every storey and outside each sleeping area.
Mount alarms on ceilings or high on walls, away from vents or fans.
Test all alarms monthly.
Replace batteries at least once a year or as soon as the unit chirps.
Vacuum around the alarm regularly to remove dust that can block sensors.
For interconnected systems, make sure all alarms sound together when one is tested.

Keeping your smoke alarms up to date is one of the simplest and most effective ways to protect your home and loved ones.

Schedule Smoke Alarm Replacement or Inspection Today

If you live in Guelph, Kitchener, Waterloo, or Cambridge and are unsure whether your smoke or carbon monoxide detectors are working properly, call Blais Electric. Our certified electricians provide expert guidance, professional installation, and peace of mind that your home is protected and code-compliant.

📞 Contact Blais Electric today to schedule a service call or smoke alarm inspection.
Your safety starts with reliable detection.

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