How to Install Smart Smoke and CO Detectors

Smart smoke and carbon monoxide (CO) detectors connect to your phone to instantly alert you to potential dangers, providing real-time notifications and remote monitoring capabilities.

Installing them properly is a little more involved than with a traditional detector, but is still easy enough for a DIYer to handle. In this video and guide, This Old House expert Scott Caron guides you through upgrading outdated smoke detectors.

Prepare for Installation

The first step is to decide how many detectors you need and where to place them. When determining adequate coverage, consider the following:

• The number of floors in your home
• The location of bedrooms and living areas
• Local building codes and regulations
• The age and condition of existing detectors

The National Fire Protection Association recommends installing smoke detectors in each bedroom and in hallways outside sleeping areas. Each level of the home—including attics and basements—should have a smoke detector, as well.

Caron points out that smoke detectors have a lifespan of about 10 years, while CO detectors typically last three to five years. If your current devices are approaching or exceeding these timeframes, it’s time for an upgrade.

Be aware that a home inspection may not catch expired detectors. As one This Old House segment revealed, inspectors typically only check two things: whether devices are in the locations they’re supposed to be and whether they make a sound. The expiration part is on you as the homeowner—you’re required to remove them and check the date yourself.

When choosing placement, keep in mind a key guideline shared during a This Old House segment: smoke detectors should go in the bedrooms, and a combination smoke and carbon monoxide detector should be placed just outside the bedrooms, typically within 10 feet of the door. This ensures that both types of hazards are detected where you’re most vulnerable—while sleeping.

Installation Process

Installing smart smoke and CO detectors is a moderately challenging DIY project that most homeowners can complete with basic tools and careful attention to safety precautions. Before beginning the installation:

1. Turn off power to the existing detectors at the main circuit breaker.
2. Gather necessary tools, including a flathead screwdriver and wire nuts.
3. Read the manufacturer’s instructions thoroughly.

Remove Old Detectors

To remove the old detectors:

1. Unscrew the mounting plate from the ceiling or wall.
2. Disconnect the wiring, noting the connections.
3. If present, cap the interconnect wire with a wire nut, as it won’t be needed for wireless smart detectors.

Install New Detectors

Why Hardwired Matters: Code requires two sources of power for new smoke detectors. The battery power you’re used to seeing is just the backup — the primary source is 120 volts of house power. A third interconnecting wire sends a communicating signal to the other devices in your house. If you have a fire down in the basement and that device goes off, you’re going to want the devices upstairs to signal as well. The interconnected wire makes that happen.

Follow these steps to install your new smart detectors:

1. Connect the provided pigtail to the house’s power supply using wire nuts.
2. Attach the new mounting plate to the electrical box.
3. Program each detector using the manufacturer’s app, assigning it to a specific room.
4. Plug the detector into the mounting plate and snap it into place.
5. Repeat the process for all detectors in your home.

Testing and Maintenance

After installation, use the test button on each device to verify proper operation. Some manufacturers provide a way to test the detectors using artificial smoke, which can offer a more realistic assessment of their performance.

Testing with Smoke: For a more thorough test beyond just pressing the button, you can use a can of artificial smoke sprayed near the detector for a couple of seconds. Give the device a few seconds to react — smart combination detectors will announce whether they’re detecting fire or carbon monoxide, so you can verify that each sensing mode is working correctly.

Ongoing Maintenance

To keep your smart detectors in top condition, regularly check the app for device status and battery levels. Clean the detectors periodically with a soft brush or vacuum attachment, and replace batteries as needed, following manufacturer recommendations. Test the devices monthly using the test button.

Integrating with Your Smart Home

One of the advantages of smart smoke and CO detectors is their ability to integrate with other smart home devices. Many smart detectors can communicate with other smart home devices, such as:

• Thermostats to shut off HVAC systems in case of fire
• Smart lights to illuminate escape routes
• Security systems to alert monitoring services

Smart Home Integration: Once all devices have been programmed, installed, and the power is back on, the system ties into your Wi-Fi. This means your smart detectors become part of your connected home network — they speak to each other along with compatible devices like smart thermostats. If a carbon monoxide alarm goes off, a compatible thermostat can actually shut off your furnaces, potentially helping to solve the problem at the source.

Smart smoke and CO detectors also often come with additional features that enhance their functionality and integration into smart homes:

• Voice integration: Many smart detectors are compatible with voice assistants like Amazon Alexa or Google Assistant, enabling you to receive alerts and manage settings using voice commands.
• Self-testing: Advanced units perform regular self-tests to ensure all sensors and batteries are working correctly, reducing the need for manual checks.
• History logs: Some detectors maintain logs of past events, allowing homeowners to review and analyze any incidents that occurred.
• Low battery warnings: Alerts can notify homeowners before battery levels become critically low.
• Sensor malfunction alerts: Immediate notifications if a detector sensor fails, ensuring continuous protection.
• Emergency Notifications: Real-time alerts in the event of smoke or CO detection, even when away from home.