First Alert CO710 review: a carbon monoxide alarm that works with the grid down

This is a research-based review, based on manufacturer specs and published data. We do not test products. Specs come from First Alert's product page for the CO710, checked November 1, 2026. Safety guidance comes from the CDC, the Consumer Product Safety Commission (CPSC) and Ready.gov.

Power outages are when households bring fuel-burning equipment close to the home: portable generators, propane heaters, camp stoves and grills. The CDC says carbon monoxide is colorless and odorless, and that people who are asleep can die from it before they notice symptoms. A CO alarm is the only warning most homes will get.

The problem is that many CO alarms depend on the grid. A plug-in alarm without a working battery backup goes silent when the power fails. The CO710 avoids that entirely: it runs on a sealed lithium battery that First Alert rates for 10 years.

Who should buy it

• Any household that will run a generator, propane heater or camp stove during an outage, including households that already have hardwired alarms.
• Renters who cannot drill or wire alarms: the CO710 is designed to sit on a shelf or tabletop.
• People who want to see a number. The ppm display and peak memory show low-level CO that may not yet trigger the alarm.
• Travelers: First Alert suggests packing it for hotels and rentals (check FAA rules for lithium batteries before flying).

Who should skip it

• Homes that need interconnected alarms that all sound together. The CO710 is a standalone unit.
• Anyone wanting a combination smoke and CO alarm. This is CO only; you still need working smoke alarms.
• Buyers who want a wall- or ceiling-mount unit. First Alert describes it as a tabletop design.

Strengths

• Outage-proof power. A sealed 10-year lithium battery means no outlet dependence, no backup batteries to forget, and no low-battery chirps for the life of the alarm (per First Alert).
• Readable data. The backlit display shows current CO, the recent peak level and room temperature. First Alert notes the peak reading can help emergency or hospital staff after a CO incident.
• Portable. At half a pound and with no mounting, it can move with the household to whichever room is heated during an outage.
• Standard listing. First Alert states it is listed to UL 2034, the US standard for residential CO alarms.
• End-of-life warning. The unit tells you when it needs replacing, so a dead sensor does not sit on the shelf unnoticed.

Drawbacks

• Whole-unit replacement. The battery is not replaceable, so at end of life you replace the alarm.
• Not interconnected. It will not trigger other alarms in the house, so place one near every sleeping area.
• Tabletop only. A shelf placement is easier to knock over or block than a wall mount.
• 85 dB. That is loud at 10 feet, but behind a closed bedroom door from a distant room it may not wake everyone. Put one in or right outside each sleeping area.

How it compares

All four alternatives below keep working without grid power. The choice is between sealed batteries and plug-in units with replaceable backup batteries.

Using it in a long outage

Where to put it during an outage

• In the room where anyone runs an indoor-rated fuel heater, such as the Mr. Heater Portable Buddy.
• In or right outside each sleeping area, especially the one closest to where a generator is running outdoors.
• On every level of the home: Ready.gov advises CO detectors with battery backup in central locations on every level.
• Follow First Alert's placement instructions for distances from fuel-burning appliances, and keep it unobstructed.

What to do if it sounds

1. 01Get everyone, including pets, outside into fresh air right away.
2. 02Call 911 or the fire department from outside.
3. 03Do not go back in until responders say it is safe.
4. 04Turn off the fuel-burning device only if you can do it without delay on your way out.
5. 05Tell responders the peak ppm reading on the display.

The CDC lists the common symptoms of CO poisoning as headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. If several people in the home feel sick at the same time, treat it as CO until proven otherwise.

Check it before storm season

Press the single button to confirm the alarm sounds, and read the display to confirm it shows zero in clean air. A sealed alarm needs no battery swap, so the only routine job is that check and replacing the unit when the end-of-life warning appears. The CPSC's Carbon Monoxide Information Center lists generator and heater precautions worth reading once a year.