Best Carbon Monoxide (CO) Detectors of 2025

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that can be extremely dangerous and even deadly if inhaled in high concentrations. Often referred to as the "silent killer," CO is produced by burning fuels such as gas, oil, wood, and charcoal. In enclosed or poorly ventilated spaces, it can accumulate quickly, leading to poisoning and severe health risks. This is why having a reliable carbon monoxide detector is crucial for every home and business, especially in the bustling Greater Toronto Area (GTA) where urban living and industrial activities are prevalent.

In 2025, the market for CO detectors has evolved significantly, offering advanced features to ensure maximum safety and ease of use. According to Global News Canada, “carbon monoxide poisoning claims the lives of more than 50 people each year in Canada. Hundreds more are sent to the hospital each year, resulting in some form of permanent disability.” As experts in security and safety systems, Alarm 24 Hours Inc. is here to guide you through the best carbon monoxide detectors of 2024 and how our services can help protect your family and property in cities like Toronto, Mississauga, Brampton, Markham, Vaughan, and beyond.

Before diving into the best detectors available, it's important to understand why CO detectors are essential:

• Early Detection: CO detectors provide early warning of CO buildup, allowing you to take action before levels become dangerous.
• Health Protection: CO poisoning can cause symptoms such as headaches, dizziness, confusion, and even death. Detectors help prevent exposure.
• Legal Requirements: In many regions, including parts of Ontario, CO detectors are legally required in certain types of buildings.
• Peace of Mind: Knowing that your home or business is equipped with a reliable CO detector offers peace of mind.

Here are the top carbon monoxide detectors of 2025, each selected for their advanced features, reliability, and ease of use.

Nest Protect (2nd Gen)

The Nest Protect is a top choice for many households due to its smart features and integration with other smart home devices. It not only detects carbon monoxide but also smoke, making it a versatile option.

Key Features:

Split-spectrum sensor to detect both fast and slow-burning fires CO detection with a 10-year sensor life Voice alarms with specific instructions Smartphone notifications and remote control via the Nest app Pathlight feature illuminates your path at night

How Alarm 24 Hours Inc. Can Help: Our team can seamlessly integrate Nest Protect into your existing home automation system, ensuring comprehensive safety and ease of use.

First Alert Onelink Safe & Sound

The First Alert Onelink Safe & Sound is another dual-function detector that combines CO detection with smoke detection. It also features a built-in premium speaker with Alexa compatibility.

Key Features:

Combination smoke and CO detection Alexa-enabled for voice commands and entertainment Mobile alerts via the Onelink Home app Interconnects with other Onelink devices for whole-home safety Hardwired with battery backup

How Alarm 24 Hours Inc. Can Help: We provide professional installation services to ensure your Onelink Safe & Sound is correctly installed and connected to your smart home network.

Kidde Nighthawk Plug-In CO Detector

For those seeking a straightforward and reliable CO detector, the Kidde Nighthawk Plug-In is a popular choice. Its plug-in design makes it easy to install and relocate if necessary.

Key Features:

Plug-in with battery backup for continuous protection Digital display shows CO levels in real-time Peak level memory to record the highest CO concentration Loud 85dB alarm for clear warnings Test/reset button for easy operation

How Alarm 24 Hours Inc. Can Help: We offer expert advice on optimal placement and provide installation services to ensure your Kidde Nighthawk is set up for maximum effectiveness.

Honeywell XC100D Carbon Monoxide Detector

The Honeywell XC100D is known for its durability and reliability. It's a great option for both residential and commercial properties, offering robust protection against CO.

Key Features:

Sealed, tamper-proof design with a 10-year lifespan LCD display for CO levels and status updates Event logging to review past incidentsLoud 90dB alarm to alert occupantsPortable and easy to install

How Alarm 24 Hours Inc. Can Help: We can help with both residential and commercial installations, ensuring that the Honeywell XC100D is properly positioned for optimal safety.

Alert Pro CO400 Carbon Monoxide Detector

For those on a budget, the Alert Pro CO400 offers reliable CO detection without the high cost. It’s a battery-operated unit, making it flexible in terms of placement.

Key Features:

Battery-operated with a low battery warning Electrochemical CO sensor for accuracy Loud 85dB alarm to alert occupants Test/reset button for regular maintenance Compact design for easy placement

How Alarm 24 Hours Inc. Can Help: Our team can assist with selecting the best locations for installation and provide guidance on maintaining your Alert Pro CO400 for long-term reliability.

At Alarm 24 Hours Inc., we understand that every home and business has unique needs when it comes to safety and security. Here’s how we can help you with carbon monoxide detection and beyond:

• Professional Installation: Our experts ensure that your CO detectors are installed in optimal locations, such as near sleeping areas and potential sources of CO, to provide maximum protection.
• System Integration: We can integrate your CO detectors with your existing alarm and home automation systems, allowing for centralized control and monitoring. This is especially beneficial for properties in Toronto, Mississauga, Brampton, and other GTA cities where comprehensive security is a priority.
• Regular Maintenance: CO detectors require regular testing and maintenance to ensure they function correctly. We offer maintenance services to keep your detectors in top condition, including battery replacements and sensor testing.
• Emergency Response: In the event of a CO alarm, quick action is crucial. Our systems can be linked to monitoring services that alert emergency responders, ensuring a swift response to potential CO leaks.
• Educational Resources: We provide resources and training to help you understand the risks of CO and how to respond in an emergency. This knowledge is essential for keeping your family or employees safe.

Our services extend across the Greater Toronto Area, ensuring that residents and businesses in all corners of the GTA have access to top-tier safety solutions. Here’s a closer look at how we serve specific cities in the region:

Toronto: As the largest City in Canada, Toronto's diverse range of residential and commercial properties requires tailored safety solutions. Whether you live in a downtown condo or run a business in North York, we can help you choose and install the best CO detectors.

Mississauga: With its mix of suburban homes and industrial areas, Mississauga residents benefit from our expertise in both residential and commercial CO detection systems.

Brampton: Rapid growth and development in Brampton mean that many new homes and businesses need up-to-date safety systems. We provide comprehensive installation and maintenance services to meet these needs.

Markham: As a hub for technology and innovation, Markham residents often seek the latest in smart home technology. Our range of CO detectors integrates seamlessly with smart home systems for enhanced safety.

Vaughan: Known for its family-friendly neighborhoods and thriving business sector, Vaughan benefits from our customized safety solutions, ensuring protection for both homes and commercial properties.

Richmond Hill: With a mix of older homes and new developments, Richmond Hill requires a diverse range of CO detectors. We offer solutions that cater to the specific needs of this growing community.

Oakville: Oakville’s blend of historic charm and modern living means that safety solutions must be versatile. Our CO detectors and services are designed to meet the unique requirements of Oakville residents.

Burlington: Proximity to industrial areas makes CO detection particularly important in Burlington. We provide reliable detectors and installation services to keep residents safe.

Milton: As one of the fastest-growing communities in the GTA, Milton requires up-to-date safety solutions. Our range of CO detectors ensures that new developments are equipped with the best protection available.

Etobicoke: With its mix of high-rise apartments and suburban homes, Etobicoke residents need flexible CO detection solutions. We offer a variety of detectors to meet these diverse needs.

Scarborough: Scarborough’s varied landscape of residential and commercial properties benefits from our tailored safety solutions, ensuring comprehensive protection against CO risks.

Newmarket: Serving the northern part of the GTA, Newmarket residents can rely on our expertise to provide effective CO detection solutions for both homes and businesses.

Ajax and Pickering: These eastern GTA cities benefit from our comprehensive safety services, including CO detector installation and maintenance for both residential and commercial properties.

Whitby and Oshawa: As part of the rapidly growing Durham Region, Whitby and Oshawa residents can count on us for reliable CO detection and safety solutions.

Caledon:The rural and suburban mix in Caledon requires versatile CO detection solutions. We provide tailored services to ensure safety in all types of properties.

Conclusion

Your safety is our top priority—whether you're sledding through winter wonderlands or safeguarding your space from carbon monoxide. Choosing the right detector can be overwhelming, which is why we’ve curated our list using a careful and thoughtful approach. First, we focused only on devices endorsed by experts, reviewed positively by customers, and vetted by trusted sources like The Spruce, Safe wise, and Popular Mechanics. Second, we filtered for reliability—every detector featured here has earned at least four stars and received praise from homeowners, renters, and even travelers. Finally, we’ve considered diverse needs: from combination alarms that detect both smoke and CO, to portable units perfect for RVs, vehicles, and camping. We also included no-installation models for convenience seekers and smart detectors that send alerts directly to your phone—keeping you informed no matter where you are.