Kidde Nighthawk AC Plug-in Operated Carbon Monoxide Alarm with Digital Display KN-COPP-3

Last updated: July 18, 2019


The Kidde Nighthawk AC Plug-in Operated Carbon Monoxide Alarm with Digital Display KN-COPP-3 measures carbon monoxide levels as low as 11 ppm. The LCD will display current CO levels, helping you keep an eye on things long before there's a problem. The alarm is 85 decibels, ensuring you'll hear it even while sleeping.

Kidde Nighthawk AC Plug-in Operated Carbon Monoxide Alarm with Digital Display KN-COPP-3

We looked at the top Carbon Monoxide Detectors and dug through the reviews from some of the most popular review sites. Through this analysis, we've determined the best Carbon Monoxide Detector you should buy.

Product Details

Key Takeaway: A loud alarm and top-notch detection make this a safe bet for your home.

In our analysis of 47 expert reviews, the Kidde Nighthawk Carbon Monoxide Alarm placed 3rd when we looked at the top 9 products in the category. For the full ranking, see below.

From The Manufacturer

Digital Display – Displays the level of carbon monoxide the unit is sensing. The unit updates this reading every 15 seconds.Protect your family from the dangers of carbon monoxide (CO) exposure with the Kidde KN-COPP-3 Nighthawk Plug-In Carbon Monoxide Alarm with Battery Backup and Digital Display. The Nighthawk is an easy-to-install unit that provides reliable protection against the dangers of CO. It features a digital display that shows CO levels in parts per million allowing you to see if, how, and when levels change.

Expert Reviews


What reviewers liked

The Kidde Nighthawk’s digital display shows the current CO levels in the house, with sensitivity as low as 11 ppm.
- Tuck
Features on this Kidde include an LED display, a level button that lets users see the peak carbon-monoxide level detected since the last reset, a sensor-on indicator, and a test/reset button.
Some alarms only tell you if your carbon monoxide levels have reached critical mass. This one will tell you if any particles are in your home, so you’ll know if there’s a leak that’s getting worse and get to safety faster.
Reviewers like the added security of knowing the exact levels of CO in their homes at all times; the Kidde KN-COPP-3 Nighthawk Plug-In Carbon Monoxide Alarm even displays CO levels that are below the threshold for alarm.
The Kidde (KNCOPP3) Nighthawk Plug-In CO Alarm with Battery-Backup has a digital interface which displays the level of carbon monoxide the unit is sensing and the highest CO level the the alarm as recorded since last activation.
Digitally displays carbon monoxide levels to easily read level changes
- Safety
Kidde’s plug in alarm still includes a battery backup so it will work if the power goes out.

What reviewers didn't like

Display accuracy is good, though not top-notch
This is only a carbon monoxide alarm. You’ll have to buy smoke alarms separately.
Alarm cannot be snoozed. Unlike other carbon monoxide detectors, the Kidde KN-COPP-3 Nighthawk Plug-In Carbon Monoxide Alarm does not allow users to snooze false alarms. The device needs to be manually reset each time.
The main downside of a plug-in alarm is that it is within reach of small kids. If you’re worried about kids tampering with the detector, you’re probably better off with one that can be mounted high up.
View our Carbon Monoxide Detector buying guide for in-depth advice and recommendations.

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