Best Smoke & Carbon Monoxide Alarms of 2026

"I have 7 interconnected alarms in my home. Whenever one goes off, they all do, which is a must-have safety feature. I used to miss alarms in different rooms, but now I’m always aware. I had an incident with incense causing smoke, and it was reassuring that the alarms alerted me throughout the house. The X-Sense detectors are worth the investment for their interconnectivity. I appreciate the easy installation and quality parts. Although the Nest Protect has some extra features, the value of X-Sense is hard to beat."

"I strongly recommend this critical safety product for anyone wanting to ensure their family is protected from fire and carbon monoxide. The 10-year battery life is a great feature since it means you won't have to worry about changing it frequently. The instructions are straightforward, and the warning signals are easy to understand. It’s definitely one of my top recommendations!"

"We replaced old detectors with 9 XSense alarms for our entire home except for bathrooms. I opted to install them on the ceiling, following best placement guidelines. The installation was mostly straightforward, but I learned that the bracket may not line up perfectly, requiring some adjustments. Pairing them was a breeze after I reread the manual. I’m confident these alarms will wake us up during emergencies, and I’m glad they should last about 10 years before needing replacement. Overall, I'm pleased with my purchase and feel much safer now!"

"I installed the detectors at both ends of my hallway just before Thanksgiving, and they worked flawlessly during some light cooking. Even with the furnace running, there were no false alarms. Installation was straightforward, but I did need to do some touch-up painting due to the smaller diameter. I found it easy to activate the unit with a flathead screwdriver; just turn the red lever on the back clockwise. When I burned food, the alarm went off, confirming it works! Resetting was simple too."

"After my family's close call with carbon monoxide, I can't stress enough how important this detector is. During a heat wave, we were running a generator and had no idea the CO levels were rising. The Kidde detector woke us up with a loud alarm, alerting us to dangerous levels. Thanks to it, we called 911 and got out safely. We had no symptoms, but the firemen confirmed we were at risk. I’ve already ordered another Kidde unit for added safety."

"I rated this product four stars because I found it a bit tricky to activate. I read reviews beforehand, which helped. The red activator switch turns clockwise, but if you accidentally turn it counterclockwise, you’ve rendered it useless. After some confusion with the light indicators, I finally saw it blink green, indicating it was working. I believe it functions well, but the activation process could be more user-friendly. If you can't find a simpler option, this is a solid choice."

"I can confirm this is a direct replacement for the outdated SC9120B. It took me roughly 5 minutes to install after swapping the trim ring, which was needed due to a slightly larger footprint. Everything worked perfectly!"

"Replacing my old First Alert Fire/Smoke alarm was a breeze. It fit perfectly and does exactly what I need it to do. I'm very satisfied with this purchase!"

"This smoke detector is a great choice for the price. It effectively detects smoke and carbon monoxide with minimal maintenance required. I'm very happy with this product!"

“I recently got my hands on the First Alert BRK PRC710 Smoke and Carbon Monoxide Alarm, and let me tell you, it's like having a trusty sidekick in home safety! The 10-year sealed battery is a game changer; no more late-night battery swaps or annoying chirps. Plus, it detects both smoke and carbon monoxide, making it a two-in-one safety device. The photoelectric and electrochemical sensors work together seamlessly, ensuring comprehensive safety. Its slim design fits perfectly in any room, and the single-button test feature is super convenient. I highly recommend installing one in every room for peace of mind!”

“I appreciate that I don’t have to change the batteries with this alarm; I can just replace the whole unit when needed. I used it to replace an older model, and while it did start randomly going off after three years, I contacted First Alert and they are replacing it under warranty. Their customer service is excellent, even if calling can be a bit of a hassle.”

“I ordered four new First Alert SMCO210 alarms and was disappointed to receive three of the new models and one outdated model, PC1210. The old one keeps beeping with a low battery warning, which is frustrating since I had to keep one of my old alarms. It seems like there is a lack of quality control in shipping, especially for a product that is supposed to ensure safety. I regret waiting two months to install them, as I missed the return window!”

"I was replacing my old detectors with this Kidde version in my new house. I’m a bit surprised the green light doesn’t stay lit like my older ones, which I preferred. The batteries work fine, and I bought extras just in case. Overall, this product is a great value and attractive."

"I just followed the manual and realized I shouldn’t test the device until it’s installed. The alarm is nice and loud, and using AAA batteries means I’ll remember to test it annually when I change them."

"I replaced my expired carbon monoxide detector with this Kidde model. It was easy to plug in and test, and I feel safer having it in the house."

“I found the installation to be incredibly simple, and the device feels solid and reliable. The clear indicators for smoke and CO alerts give me peace of mind knowing my home is protected. The alarm is very loud, which is particularly beneficial in emergencies. I highly recommend it for any household!”

“I have four of these detectors in my home. When one goes off, it triggers the others, ensuring I’m aware of any alarms throughout the house. This interconnectivity was a major reason for choosing this model, and I can confirm it works as advertised.”

“I was surprised to learn that starting my car in the garage with the door open could impact my living space. After doing it, the alarm went off and it warned me to open the garage door and windows. I will definitely pull my car out right away from now on!”

"I've been using Kidde products for years. They are dependable and reasonably priced. I feel safe knowing my family is protected with a Kidde product. A+++++!"

"This unit promised more than a regular smoke detector. It's held up well, but it really needs fresh batteries for the best reliability."

"I chose this CO and smoke dual sensitivity alarm because of its UL certification and affordability. It was simple to install, came with batteries, and the test alarm was loud and easy to silence."

"At around 2 AM, my alarm started chirping. I swapped the batteries after just a month. It chirped again the next month, and I suspect my rechargeable batteries weren't fully charged. After a few months, I heard the chirping again at 2 AM. Why not during the day? This seems like a craftsmanship issue. I'm thinking of changing brands!"

"I had to replace my smoke alarms after 7 years. I bought these to replace the same brand, and it was an easy switch out. Now I can sleep well again."

"When we moved in, there were no carbon monoxide detectors. After upgrading to a gas furnace, I wanted to ensure our home was safe. I chose the Kidde Hardwired Smoke & Carbon Monoxide Detector because of its great reviews and battery backup. The installation was a breeze and took just a few minutes. I love that when one alarm goes off, they all alert together. I will definitely buy Kidde detectors again!"

"I replaced my old hardwired smoke detector in about 5 minutes. This one has a carbon monoxide detector included, which is exactly what I needed. Overall, it's a good product."

“I ordered this Kidde Smoke/CO detector to match my wired units at home. I did need to change the pigtail, but it was provided with the unit. I found the three-wire connection easy to handle, and it works great!”

“I replaced my old smoke detectors with these new ones. The previous ones were chirping due to age, but these have the extra wire for interconnection, just like my old units. I had to rewire the plug-in connector, but it was manageable. I love that these alarms not only sound a loud alarm but also verbally announce whether it's a fire or carbon monoxide alert. The interconnection among all six detectors is seamless!”

“Finding detectors that meet the necessary codes was challenging, but these did the job in my state. They look good, and my client was pleased. The installation was straightforward, and I haven't had a single callback in the past two years.”

"I've always trusted First Alert products, so it was a no-brainer for me to choose this newer model. They fit seamlessly with my previous 9120B units, making installation a breeze. I did swap out the yellowed mounting collar for appearance, but it was easy to do with the keyhole slots. Plus, I love that it has carbon monoxide detection and a 10-year rechargeable battery—no more chirping at 2 AM!"

"After moving in, my smoke/CO detectors started making odd beeping sounds even though the batteries were fine. I discovered they expire after ten years due to natural sensor degradation. I appreciate that these new models have a sealed, non-replaceable battery that lasts the entire decade. They're straightforward to install, and if you have a wired system, it’s just plug-and-play. Overall, I’m thrilled to avoid yearly battery changes!"

"Installing these alarms was a piece of cake. They plugged right into the original wiring, and the initial beep was LOUD! I followed the instructions easily, and it took me only about 10 minutes to install all three units. I'm very satisfied with my purchase!"