Combination Smoke & Carbon Monoxide Alarm

Safety

First Alert

Combination Smoke & Carbon Monoxide Alarm

Ten-year sealed battery, two hazards, one device.

4.727,400 Amazon ratings$39
Sentinel ChoiceNew Homeowner PickBest Seller

Read why Sentinel recommends this below. Buying options are at the end of the page.

Installation difficulty

Easy

Estimated time

15 minutes

Warranty

10 years

Why we recommend it

Covers both smoke and carbon monoxide with no battery swaps. It is most useful for every bedroom hallway and each floor of the home. Compatible with any residential ceiling or wall mount.

When you’ll need it

  • Immediately if any alarm is over 10 years old
  • When moving into a home
  • On every level of a home with combustion appliances

Who benefits most

  • Every household
  • Homes with gas or oil heating
  • Homes with attached garages

Before you buy

Honest guidance — you may not need this at all

  • Check the manufacture date on the back of your existing alarms — replacement is by date, not by looks.
Professional tip

Photograph the manufacture date on the back before mounting. That date, not the install date, drives replacement.

What it does

  • 10-year sealed battery
  • Photoelectric smoke sensing
  • Electrochemical CO sensing

Maintenance tips

  • Press test monthly.
  • Vacuum the housing twice a year.

Frequently asked questions

How many do I need?

One per bedroom, one outside each sleeping area, and at least one per floor including the basement.

Ready to purchase?

If this product fits your home's needs, you can purchase it through one of our trusted retail partners.

Why this matters

Spending $25–$75 today on preventive maintenance can often help homeowners avoid repairs that cost hundreds or even thousands of dollars later. Sentinel Home recommends products that support long-term home protection — not impulse purchases.

Retailer:
Amazon
Last verified:
Jul 30, 2026