Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm Review

This CO alarm offers easy setup and several mounting options

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5

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm

 The Spruce

What We Like

  • Three mounting options offer installation flexibility

  • Easy to setup

  • Bright digital display

  • Loud alarm

  • Alerts you when batteries are low

What We Don't Like

  • Intermittent beeping noise may take you a while to notice

  • Without instructions, display messages can be confusing

  • Only detects carbon monoxide, not smoke

Bottom Line

The Kidde Nighthawk AC Plug-in Operated Carbon Monoxide Alarm is everything a good carbon monoxide (CO) detector should be—simple yet effective. It also offers plenty of installation options, so you can place it near most electrical outlets. 

5

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm

 The Spruce

Carbon monoxide poisoning is no joke—so if your home doesn’t come equipped with a CO alarm, you should install one immediately. The Kidde Nighthawk CO alarm plugs right into most outlets, making it exceptionally easy to protect yourself and loved ones from the odorless, colorless gas. It’s not just the alarm’s plug-and-play design that makes a great option, though; keep reading to see how the Kidde Nighthawk meets almost every criterion for a great carbon monoxide alarm.

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm
The Spruce 

Setup Process: Fast and easy

We have to start with setup because that’s where the Nighthawk really shines. It offers three installation options: direct plug-in, wall mounted, and tabletop. After going through the process ourselves, the direct plug-in and tabletop installations proved to be as simple as they come.

For direct plug-in, all you have to do is open the back, install the battery, and plug the alarm into an outlet. You can even take out the adapter and rotate it so the alarm can be mounted on horizontal outlets. The slide support—located on the back at the bottom—locks into several positions and needs to be used when the alarm is plugged directly into an outlet or used on a tabletop as it supports the alarm’s weight. Sometimes, heavier plug-in devices pull the plug out of the outlet, but we didn’t have this issue so long as the slide was in place. 

Tabletop installation is even easier than direct plug-in; you put the battery in, remove the adaptor and cord, plug in the alarm, and set it on the tabletop with the slide support extended.

The third installation option—wall mounted—is slightly more labor intensive. The alarm includes two mounting screws and anchors (for plasterboard or drywall). If you choose to wall mount, you’ll need a screwdriver or drill. You’ll also have to make sure the alarm is within six feet of an electrical outlet because it still needs to be plugged in to operate correctly.

Installation: Choose your location with care

Carbon monoxide detectors can’t be installed just anywhere, and this one is no different. Even though installation isn’t difficult, you have to read through all the instructions before installing to make sure you’ve chosen a location that allows the alarm to work to its full potential.

The alarm comes with detailed instructions as to the appropriate locations. For example, you should avoid the garage, anywhere near a window or vent, and any space within five feet of a heating or cooking appliance. There are also instructions about the ideal height of installation (within three feet of the floor is best). You can’t slap it up just anywhere, but we didn’t have a problem finding a location that met all the requirements.

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm
The Spruce 

Performance: An alarm that gets your attention

The Nighthawk has only two buttons, one of which is a test button. Once we got the battery in and the unit installed, we tested the alarm. The volume definitely gets your attention. There were children in another room, and they were on high alert once the alarm started sounding. It detects both low and high levels of CO, though it tends to be more accurate at higher levels. Our testing didn’t get into dangerous levels, but it quickly went off in the mid-range.

Once we got the battery in and the unit installed, we tested the alarm. The volume definitely gets your attention.

However, it’s not like a fire alarm with a consistent beep going off repeatedly. Instead, there are four beeps followed by five seconds of silence before it repeats the pattern. The display then shows the carbon monoxide level—a number between 0 and 999ppm (parts per million). A reading of 0 to 50ppm is normal and safe, 50 to 100ppm isn’t dangerously high but should definitely be addressed. If you see a reading in this range, you need to ventilate the area and immediately find the source of the CO. Anything over 100ppm is dangerously high, and the area should be evacuated. 

This alarm can’t be ignored, but if you were asleep in another room when it started to go off, the intermittent pattern might take longer to wake you, especially in comparison to a constant beeping. However, if you were sleeping in the room where the alarm is installed, there’s really no way you could sleep through it for long.

Design: The right size for a digital display

The Nighthawk is roughly the size of your average smoke alarm. (Please note: It does not detect smoke or fire.) If plugged into the bottom plug of an electrical outlet, you’ll still be able to use the other plug.

The digital display is a good size for the size of the alarm. We tested visibility from about 15 feet away, and the bright red numbers are easily visible. It’s not an attractive device, but it doesn’t call attention to itself, especially when used as a plug-in or wall mounted model. It also has a peak level memory, which allows you to see the highest CO level the alarm has detected since its last reset.

Long-Term Safety: Reminders til the end

The Nighthawk isn’t battery powered, but it does have a backup battery in case of a power outage. If the unit comes loose from the plug or if the battery dies, a single beep that repeats every 15 seconds will start to sound so you know you’re now on battery power and a time limit before the battery runs out.

After ten years, the Nighthawk’s end of life alarm will sound repeatedly to let you know it’s time to replace the whole unit. That really gave us some peace of mind. After all, we’re usually trying to remember when we need to change filters, batteries, or pumps in various devices and appliances. The fact that this one will let us know when it’s nearing the end of its life is one less thing to worry about.

After ten years, the Nighthawk’s end of life alarm will sound repeatedly to let you know it’s time to replace the whole unit. That really gave us some peace of mind.

Kidde Nighthawk AC Plug-In Operated Carbon Monoxide Alarm
The Spruce 

Understanding Carbon Monoxide: Instructions with depth

The instructions that come with the Nighthawk are more than a step by step guide to installation. They give detailed instructions as to what carbon monoxide poisoning is, the symptoms, and the actions to take. There are also two stickers that provide a space for an emergency number and contain safety instructions if the alarm detects high CO levels.

You’ll probably have to hang onto the instructions for the life of the alarm to understand the display messages, including CO levels. They can be folded and tucked underneath or behind the alarm, though.

Price: Middle of the pack

At $69.99, the Nighthawk falls in the higher mid-price range for carbon-monoxide-only detectors but is definitely on the low end if you include smoke/carbon monoxide detectors with smart capabilities. If you want a model with installation flexibility, an easy to read display, and only need to add carbon monoxide detection to your space, it’s a pretty good (and safe) deal.

Competition: A Good standalone option

Nest Protect Smoke and Carbon Monoxide Alarm: The Nest provides all-in-one detection for fire and carbon monoxide, which means fewer devices in your home. You can pair it with your phone to get alerts while you’re away or to simply check up on things. It’s a good choice if you want to replace your standard smoke alarms with a two-in-one option, but it will run you much more at roughly $120.

Kidde 9CO5-LP2 First Alert Carbon Monoxide Alarm: The Kidde First Alert is a battery-powered alarm that can be wall mounted or used on a tabletop. It requires more battery changes and doesn’t have all the installation options of the Nighthawk, but it’s reliable if you need something that’s strictly battery operated and you can grab one for less than $20.

First Alert CO605 CO Alarm: The First Alert CO Alarm is a plug-in or wall-mounted model that doesn’t have all the installation options or digital displays of the Nighthawk. However, it can’t be ignored when it gets triggered. It’s loud and equipped with an end of life signal so you’re never left unprotected. It’ll also run you just $20.

Final Verdict

Yes, if you don’t also need smoke detection.

If you don’t want or need a dual smoke/carbon monoxide detector nor do you want to add a smart device to your home, the Nighthawk is an excellent choice. The installation options and accuracy of the CO detection make it a purchase worth making.

Specs

  • Product Name Nighthawk AC Plug-In Operated Carbon Monoxide Alarm
  • Product Brand Kidde
  • MPN KN-COPP-3
  • Price $69.99
  • Weight 1.06 lbs.
  • Product Dimensions 6.06 x 3.75 x 1.75 in.
  • What’s Included Carbon monoxide detector and 9V battery