Kidde AC Plug-in Carbon Monoxide and Explosive Gas Detector Alarm | Nighthawk Sensor Technology | Model # KN-COEG-3

Good CO detector, has 12v backup battery and 110 v plug in main power supply with a long (4’cord). This is a replacement for the first one I purchased 5 years ago. These units have a 5 year design life once they are plugged in. After 5 years of operation they automatically stop working and sound an alarm and message to replace the unit. I like the display, bright and legible red lettering and the alarm is loud enough for me to hear it upstairs even though it’s located in the basement. Yes, I will probably purchase again.

Year old, with a bad battery. I ordered and received the unit the same day. It was new old stock (NOS) made late 2024. Not idea. AND even worse, as soon as I plugged it in, the unit alarm started sounding with what looked like an "L6" error display. Turns out that was actually a "L" as in "Low" and "b" as in "battery". So I checked and indeed the shipped bat was low. I replaced it, after calming my family down about false alert, and the unit is now working properly. I'm ordering two more and will update this review if those two are newer and/or have good batteries.

This is something I consider a necessity. The size is not obtrusive and the design is simple. It can be plugged in a wall outlet directly or the plug can be removed from the holder to reveal a cord so it can be set on a shelf if needed. It has a battery backup. The alarm is loud so you will hear it if detection is made. It is easy to read the display. The only thing I was a little annoyed at is that it was made a year ago so we lost a whole year on the lifespan.

Item arrived in timely manner. However, unit was dated (December 2024) and the battery was dead. Unit is supposed to be good for 7 years but I lost 1 year because unit was already over a year old. Probably reason. battery went dead. Unit has a 5 year warranty - already lost 1 year of warranty. Since I just installed the unit, I can't speak about the product as yet. The volume is loud which is a plus. The door on back of unit to install battery was very difficult to open. If you have weak hands or arthritis you will need someone else to help you. Unit must have the battery installed or you get continuing beeping. The display on unit is easy to read. The unit is large and a bit bulky (wish it had been smaller). The manual is hard to read and there are no instructions in it on how to replace battery.

Haven't seen such a well engineered product in years. It has a plug that is snug for wall mounting, can be rotated, and can even be detached to use as a power brick. Battery backup and comes with a Duracell battery. Documentation seems like it was written by an engineer a tad, but it's a great product. Has a small kickstand too. As far as plastic goes, it seems like it's very good quality. The test works well. Nice to see 0 PPM of explosive gas in the home. Hopefully I never have to review its detection ability. Great job, Kidde, and please don't let your product slide like 95% of modern companies are.