Live nowPrime Day 2026October 6 to 7, 2026Starts in--d--h--m--sSee the deals
Smoke & CO Detectors · Head to head

First Alert SC5 Hardwire Smart Smoke & CO Alarm vs Shelly Plus Smoke Alarm

Full Smart Smoke & CO Detectors comparison in 2026

Data from Amazon and official First Alert and Shelly sites.
2026 verdict
Smoke-only versus dual-hazard: the Shelly Plus Smoke Alarm takes this comparison on price, owner rating, and a wider connectivity and integrations spread: Google Home, Samsung SmartThings and Home Assistant.
Shelly Plus Smoke Alarm
Winner
Shelly Plus Smoke Alarm
€52.54€59.9912% OFF
Buy on Amazon Italy
It is a battery-powered, hub-free WiFi detector with a built-in light and automation support, well suited to smart-home tinkerers, but it only watches for smoke and leaves carbon monoxide uncovered. The SC5 Hardwire lists Google Home but no SmartThings, and its Home Assistant support is not documented. The First Alert SC5 Hardwire Smart Smoke & CO Alarm counters with combined smoke and carbon monoxide detection, a longer 10-year warranty, and steam-check tuning to cut kitchen and shower false alarms, all running on mains power with a battery backup rather than replaceable cells alone. Anyone whose home lacks separate CO coverage, or who already has alarm wiring in place, should lean toward the SC5 Hardwire, while automation-minded households that have CO covered elsewhere and want broad platform support can save with the Shelly Plus Smoke Alarm.
vs
Deals by email

Smoke & CO Detector prices change while you decide

We follow prices across the catalog and email you the best deals we find.

Smart home deals and news, straight to your inbox

Price drops, new releases and the smart home news worth knowing.

No spam. Unsubscribe in one click.

Your subscription could not be saved. Please try again.
Please enter a valid email address.
Your subscription has been successful.
FeatureFirst Alert SC5 Hardwire Smart Smoke & CO AlarmShelly Plus Smoke AlarmWinner
Rating3.24.4Shelly Plus Smoke Alarm
Warranty10 years3 yearsFirst Alert SC5 Hardwire Smart Smoke & CO Alarm
Connectivity2.4 GHz WiFi2.4 GHz WiFi, BluetoothShelly Plus Smoke Alarm
IntegrationsGoogle HomeGoogle Home, Samsung SmartThings, Home AssistantShelly Plus Smoke Alarm
SensorsSmoke, COSmokeFirst Alert SC5 Hardwire Smart Smoke & CO Alarm
AlertsFire Alerts, CO Alerts, Low Battery AlertsFire Alerts, Low Battery AlertsFirst Alert SC5 Hardwire Smart Smoke & CO Alarm
Built-in LightNOYESShelly Plus Smoke Alarm
Steam CheckYESNOFirst Alert SC5 Hardwire Smart Smoke & CO Alarm
ScreenNONOTie
Built-in SirenYESYESTie
Tests ItselfNONOTie
PathlightNONOTie
Winner
Shelly

Shelly Plus Smoke Alarm

12% OFF
Prime exclusive deal
€52.54
€59.99
Buy on Amazon Italy
  • + Rating: 4.4
  • + Connectivity: 2.4 GHz WiFi, Bluetooth
  • + Integrations: Google Home, Samsung SmartThings, Home Assistant
  • - Warranty: 3 years vs 10 years
  • - Sensors: Smoke vs Smoke, CO

Price history compared

Every price change of both, in the same store, so the gap between the two lines is what one costs more than the other.

  • First Alert SC5 Hardwire Smart Smoke & CO Alarm
  • Shelly Plus Smoke Alarm

Loading price history...

Frequently Asked Questions

Which is better overall: the First Alert SC5 Hardwire Smart Smoke & CO Alarm or the Shelly Plus Smoke Alarm?

The Shelly Plus Smoke Alarm comes out ahead overall, winning on price, owner rating, and broader WiFi/Bluetooth connectivity plus a wider integrations list (Google Home, Samsung SmartThings and Home Assistant). The First Alert SC5 Hardwire Smart Smoke & CO Alarm still wins on hazard coverage and warranty length.

What is the biggest difference between these two alarms?

Hazard coverage and power source. The First Alert SC5 Hardwire Smart Smoke & CO Alarm detects both smoke and carbon monoxide and runs on mains power with a battery backup, while the Shelly Plus Smoke Alarm is smoke-only and runs entirely on a replaceable battery with no wiring needed.

Does the Shelly Plus Smoke Alarm detect carbon monoxide?

No. It is a smoke-only detector with no CO sensor or CO alerts, so a household that needs carbon monoxide protection would need a separate device, unlike the First Alert SC5 Hardwire Smart Smoke & CO Alarm, which covers both hazards in one unit.

Which alarm works with more smart home platforms?

The Shelly Plus Smoke Alarm connects to Google Home, Samsung SmartThings and Home Assistant. The First Alert SC5 Hardwire Smart Smoke & CO Alarm works with Google Home, has no SmartThings support, and its Home Assistant support is not documented.

Who should buy the First Alert SC5 Hardwire Smart Smoke & CO Alarm?

Homeowners with existing hardwired alarm circuits who want one unit covering both smoke and carbon monoxide, plus steam-check tuning to reduce cooking and shower false alarms, and who are already invested in Google Home.

Who should buy the Shelly Plus Smoke Alarm?

Smart-home enthusiasts who already have carbon monoxide detection covered and want a hub-free WiFi smoke alarm that plugs into Home Assistant, MQTT automations, or a broader mix of Google Home and SmartThings routines.

Full comparison table

Compare all 25 Smoke & CO Detectors side by side

You are looking at two of them. The full table lines up all Smoke & CO Detectors in the catalog with the same specs, so you can filter by what you need and sort by price or rating.

  • 25 Smoke & CO Detectors
  • 44 specs compared
  • 41 filters
Open the full comparison
More Smoke & CO Detectors

Top Smoke & CO Detectors to compare next

25 smart smoke and CO detectors from 9 brands compared: X-Sense, First Alert, Kidde, Google Nest and more. Sensor types, interlink and alerts.

All Smoke & CO Detectors
First Alert

More First Alert products

A sharper look at other First Alert products worth comparing.

Explore First Alert
Shelly

More Shelly products

A sharper look at other Shelly products worth comparing.

Explore Shelly
Independent · Not sponsoredBrands never pay for placement or rankings. Affiliate commissions never influence our comparisons.
© 2026 Smart Home Compared
Search