Safety
First Alert
First Alert SMCO210 10-Year Smoke & CO Alarm
Recommended when an existing alarm is past its service life or a home has combustion appliances without CO detection.
Price, rating, availability, and delivery details are shown on Amazon. Sentinel publishes those figures only after an administrator verifies them.
Alarm placement and quantity are governed by local code. Confirm required locations for your home before ordering.
Read why Sentinel recommends this below. Buying options are at the end of the page.
Installation difficulty
Easy
Estimated time
15 minutes
Warranty
Not applicable
Why we recommend it
Recommended when an existing alarm is past its service life or a home has combustion appliances without CO detection. It is most useful for surfaced with heating-season safety checks, alarm replacement guidance, and combustion-appliance education.. Compatible with alarm placement and quantity are governed by local code. confirm required locations for your home before ordering..
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.
Read the manufacturer's instructions once before you start — most homeowner mistakes happen in the first five minutes.
What it does
Maintenance tips
Frequently asked questions
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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:
- Aug 12, 2026