First Alert SC5 Hardwire Smart Smoke and CO Alarm - Best for Google Home and Nest Protect Integration

A premium hardwired smart alarm that seamlessly integrates with Google Home and existing Nest Protect ecosystems, offering robust safety with smart home automation.
- +Designed as a direct replacement and can interconnect with existing Nest Protect units
- +Features a large, easy-to-press physical hush button for silencing without an app
- +Integrates seamlessly with Google Home app and compatible smart locks for automated safety responses
- -Significantly more expensive than other smart alarm options
- -Lacks desirable Nest Protect features like pre-alarm voice warnings and a pathway night-light
- -Smartphone notifications can be delayed by 45 seconds or more after alarm activation
Positioned as the official successor to the discontinued Nest Protect, the First Alert SC5 Hardwire Smart Smoke and CO Alarm caters specifically to users invested in the Google smart home ecosystem. Its primary advantage is compatibility; it can wirelessly interconnect with legacy Nest Protect devices, allowing for a hybrid system. It also integrates natively with the Google Home app for centralized management and can work with Resideo smart-home products. For safety automation, it can be configured to trigger actions like unlocking Kwikset or Schlage smart locks during a fire to facilitate escape. The alarm features a thoughtful, fail-safe hush function: the app can silence it, but if smoke levels remain high, it will not allow silencing, preventing a user from accidentally disabling a legitimate alarm.
Installation is guided by voice prompts, and the physical design includes a large, concave hush button that is easy to press with a broom handle—a user-friendly detail. However, the SC5 comes at a premium price while omitting several beloved features of the Nest Protect, such as the pre-alarm voice warning that gave occupants a chance to address a minor issue before a full alarm sounded, and the motion-activated pathway night-light. Another notable drawback is the latency in smartphone notifications, which in testing took around 45 seconds to arrive—a significant delay during an emergency. It also lacks the automated self-testing of its predecessor. For those with a Google-centric smart home or an existing investment in Nest Protect devices seeking a certified, hardwired upgrade, the SC5 is a capable choice, but its high cost and missing features are important considerations.