Replacing an existing hardwired smoke detector is very easy and takes about 10-15 minutes. However, adding a new hardwired detector where no wiring exists is a difficult, advanced DIY project involving cutting drywall, running cables through walls, and connecting to your home's main electrical panel.
Yes, you can absolutely install a hardwired smoke alarm yourself. However, because you are dealing with your home's 120V electrical system, you should only attempt this if you are comfortable with basic electrical work and strictly follow safety protocols.
Hardwired smoke detectors are connected to your home's electrical system, and improper installation or handling of electrical connections can be dangerous. An electrician has the expertise to disconnect the old smoke detectors, install the new ones, and test them to ensure everything is working correctly.
The primary smoke detector that works with Google Nest is the Google Nest Protect (2nd Gen), which is designed for full integration with the Nest app, phone alerts, and other Nest devices. As an alternative, the First Alert SC5 Smart Smoke & CO Alarm is an officially recommended partner that works alongside Nest Protect in the Google Home app.
Here's an estimated breakdown of the hardwired smoke alarm installation cost and battery-operated options: Battery-operated smoke alarms: $10 – $50 per unit, plus $50 – $100 for installation. Hardwired smoke alarms: $30 – $150 per unit, with installation costs ranging from $150 – $300 per alarm.
Some fire departments offer reduced-price, or even free, smoke alarms. Contact your local fire department's nonemergency phone number for more information. Your city, county or state may require a specific type of alarm. Please check with your local fire marshal for information on what type of alarm you need.
Hardwired smoke detectors have a maximum lifespan of 10 years from the date of manufacture. Even though they are connected to your home's electrical wiring, the internal sensors degrade over time from dust and humidity, meaning the entire unit must be replaced after a decade.
Firefighters recommend dual-sensor smoke alarms (which combine both photoelectric and ionization technology) or interconnected alarms. They also stress that the brand matters less than choosing models featuring 10-year sealed batteries and ensuring you have detectors on every floor and outside all sleeping areas.
If you are replacing an expired Nest Protect, the recommended replacement is the First Alert SC5 Smart Smoke & CO Alarm. This device was developed in collaboration with Google and is designed to act as a seamless, direct swap for Nest Protects on your existing mounting plates and wiring harnesses.
If you're replacing an existing wired alarm, a hardwired model will likely be the best option. If you're starting new or adding alarms, battery-powered may be the more flexible choice. For whole-home safety, make sure alarms are installed in every bedroom, outside sleeping areas, and on every level of your home.
Generally, fire departments will not repair or replace smoke alarms. They may offer help with smoke alarm installation or testing, particularly for vulnerable groups or in the context of a fire safety program, but will not provide routine repairs.
The best smoke detectors are split between trusted, traditional alarm manufacturers and smart home brands. Kidde is the top overall choice for reliable hardwired units, First Alert (or BRK) excels in dual smoke and CO safety, and Google Nest is the premium pick for smart features.
Always shut off the circuit breaker before touching a hard-wired detector — the 120V AC supply is live even with the battery removed. After replacement, test every detector in the interconnected system by holding the TEST button — all units should alarm together.
If your home was built after 1986, it will have at least one hard wired smoke alarm connected directly to your electrical panel. It is not acceptable to replace a hard wired alarm with one that is battery operated. A home must maintain at least the same level of protection as originally required. It is the law.
Most newer construction homes in the United States are installed with hardwired smoke detectors that are powered by household AC current, each have a battery for backup, and have a wired interconnect so all stations alarm when smoke is detected.
The US National Fire Protection Association (NFPA) have issued NFPA Standard 72, National Fire Alarm and Signalling Code, which states that all smoke alarms (including alarms that use 10 year batteries, and those that are hard wired) should be replaced when they are ten years old, or sooner if they don't respond ...
What this means for you: Starting October 25, 2025, your device will be unpaired and removed from your Nest app or Home app. This also removes third-party assistants and other connected or cloud-based features like Home/Away Assist and multi-device Eco mode control.
Your new First Alert SC5 Smart Smoke & CO Alarm will work seamlessly alongside your other Nest Protect devices and will work with the Google Home app.
The best smart smoke detectors of 2026 combine reliable multi-sensor fire and carbon monoxide detection with instant mobile alerts, remote silencing, and whole-home interconnectivity. Top models integrate effortlessly with major smart home ecosystems like Google Home, Amazon Alexa, or Ring.
Yes, you should get a combination smoke and carbon monoxide (CO) detector, as they save space, simplify maintenance, and reduce the number of devices you have to manage. They are highly recommended for covering two critical life-safety needs in one unit.
A: BRK tends to have higher ratings for reliability and fewer false alarms, while Kidde is often rated well for affordability.
The "best" smoke detector depends on your home’s wiring and how you want to receive alerts. The top overall recommendation is the Kidde smart smoke/CO detector, which delivers excellent fire detection with optional Wi-Fi app alerts.
Yes, hard-wired smoke detectors must be replaced. Even though they are connected to your home's electrical system, their internal sensors degrade over time due to dust, humidity, and airborne contaminants.
Even after the battery has been removed, the detector maintains a residual charge that will keep the chirp going for some time. To get the device to stop chirping once the battery has been removed, you must drain this residual charge by holding the test button for 15 seconds.