First Alert Smoke Alarm

Last updated date: April 6, 2019

Review Melt Score
8.5

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We looked at the top 1 Carbon Monoxide Detectors and dug through the reviews from 6 of the most popular review sites including New York Times Wirecutter, Tuck, Home Safety Dot, B4 Best Reviews, Safety Products Unlimited and more. Through this analysis, we've determined the best Carbon Monoxide Detector you should buy.

Overall Take

In our analysis of 59 expert reviews, the First Alert First Alert Smoke Alarm placed 7th when we looked at the top 10 products in the category. For the full ranking, see below.

Editor's Note April 15, 2019:
Checkout The Best Carbon Monoxide Detector for a detailed review of all the top carbon monoxide detectors.

Expert Summarized Score
9.2
6 expert reviews
User Summarized Score
7.1
757 user reviews
Our Favorite Video Reviews
What experts liked
Because they’re interconnected, the SA511CN2-3ST alarms not only give you an early warning but also tell you where the problem is originating from.
- New York Times Wirecutter
The First Alert SA511CN2-3ST combines the security of interconnected systems with the ease of installation of battery-only smoke detectors.
- Tuck
It is battery operated smoke detector with a helpful voice location.
- Z7 Premium
The SA511CN2-3ST uses photoelectric sensors. This means that it can detect visible smoke particles, which are associated with smoldering fires.
- Home Safety Dot
The smoke detector is equipped with a photoelectric sensor that is intended to detect smoke, but minimizes the number of false alarms caused by smoke or shower steam.
- B4 Best Reviews
Not only is it a wireless smoke alarm that can wirelessly connect throughout your home, the Voice Location will tell you exactly where the fire is, saving valuable time by directing you to the right location.
- Safety Products Unlimited
What experts didn't like
The main downside to our First Alert pick is that the wireless units are available only with photoelectric sensors—none of the company’s ionization alarms have wireless connectivity.
- New York Times Wirecutter
Connecting multiple units can be problematic
- Home Safety Dot
Durability. No long run.
- B4 Best Reviews
The batteries are drained faster than with other comparable models.
- Safety Products Unlimited

From The Manufacturer

This First Alert SA511CN2-3ST Interconnected Wireless Smoke Alarm with Voice Location features an 85-decibel siren and voice alarm with 11 programmable locations that tells you where the danger is located. A photoelectric sensor detects smoke while minimizing false alarms from cooking or shower steam. These interconnected smoke detectors come in a convenient pack of 2 and are designed to work together throughout your home, with one alarm triggering the other alarm during an emergency, creating a home safety network. You can wirelessly connect it with up to 18 other First Alert enabled alarms in your home. The battery-operated alarms don't require hardwiring for installation and will provide con tinued monitoring even in the event of a power failure. In the event of a fire every second counts. If a fire were to begin in your basement and the alarm there sounded, you may not hear it right away if you're sound asleep two floors up. With traditional battery-operated alarms, you lose valuable time waiting for the smoke to rise to another alarm, on another level, before the alarm on your floor sounds. But with First Alert ONELINK alarms, if one detects danger, they all sound. This can alert you sooner, and it increases your chances of getting out safely. Until now, alarms that could signal each other were only available in homes with hardwired alarms requiring installation from an electrician. But First Alert ONELINK alarms communicate without wires. ONE Link-with Voice Location Smoke alarm is programmable with up to 11 locations in your home - when alarm sounds it will tell you the location of the smoke. The wireless feature allows multiple alarms to talk to each other - when one alarm sounds, they all sound. The wireless network operates on 914 MHZ 3 channels and will not interfere with other electronics. The ONELINK smoke alarms uses photoelectric sensing technology which is environmentally friendlier and which reduces nuisance alarms, making it ideal for cooking areas. It is also great for sensing slow smoldering fires quickly. A low battery signal alerts you to replace the battery. The test/silence button both silences a non-threatening alarm or low battery warning and allows you to test the unit's functionality. The AA batteries are easy to install in the convenient pullout battery drawer. Two AA batteries included.

Overall Product Rankings

1. Nest Protect Smoke and Carbon Monoxide Alarm
Overall Score: 9.5
Expert Reviews: 9
3. First Alert Carbon Monoxide Alarm
Overall Score: 9.3
Expert Reviews: 5
4. Alert Plus Carbon Monoxide Alarm Detector
Overall Score: 9.1
Expert Reviews: 2
7. First Alert Smoke Alarm
Overall Score: 8.5
Expert Reviews: 6
8. Sensorcon Carbon Monoxide Detector
Overall Score: 8.0
Expert Reviews: 6
9. Kidde Battery Operated Carbon Monoxide Alarm
Overall Score: 7.7
Expert Reviews: 5
10. Roost PP3 (9v) Specialty Battery
Overall Score: 7.1
Expert Reviews: 4

An Overview On Carbon Monoxide Detectors

It’s known as the silent killer. An odorless, colorless gas, carbon monoxide seeps into a home and gradually poisons its occupants, killing an estimated 400 people per year. Symptoms are commonly mistaken for the flu, leading sufferers to delay getting treatment until it’s too late.

The Centers for Disease Control says one of the best ways to prevent carbon monoxide poisoning is to install a detector in your home and update your batteries at least every six months. You’ll need to place it close to your master bedroom to ensure you hear any late-night alerts and replace the detector at least every five years.

But the first step in protecting your family against carbon monoxide is to choose a good detector. There are many on the market that will do the job, but some features are more important than others. You can find a detector that will display carbon monoxide levels at all times, giving you reassurance it’s actively monitoring the safety of the air you’re breathing.

If you don’t already have functioning smoke detectors in your home, you may want to consider a unit that will protect your home against fire as well as carbon monoxide. You may also want to consider purchasing a device that links up to smoke detectors so that all of your devices communicate with each other.

You’ll notice some carbon monoxide detectors are wired while others are battery-powered. If you choose a wired model, make sure it has a battery backup that kicks in if the power goes out. Whether it’s battery-powered or wired, though, you’ll need to change the batteries at regular intervals. Experts recommend updating the batteries in your smoke and carbon when you adjust your clocks for Daylight Savings Time to keep the task easy to remember. However, you can buy detectors that will alert you when the battery is low.

Review Melt Fun Fact

In addition to buying a carbon monoxide detector and maintaining it, there are a few other things you can do to keep your family safe. Oil, wood and gas furnaces are common sources of CO, as are gas stoves or dryers. If you use a gas or oil water heater, candle or a gas lantern, you may also be at risk. One important preventive measure you can take is to schedule regular inspections of any gas, oil or coal-burning appliance. You should also never use a generator or other CO-emitting appliance inside your home. If you have an attached garage, avoid running a vehicle inside it, even if you have the garage door open.

The Carbon Monoxide Detector Buying Guide

  • Before you buy a carbon monoxide detector, you’ll need to understand safe levels. These can vary from household to household, depending on the length of your exposure and the overall health of each person who lives there. Occupational Safety and Health Standards require workplaces to keep levels below 50 ppm, but many people won’t experience symptoms until at least 70 ppm. Heart patients may begin experiencing chest pains as levels rise within that range, though. Once carbon monoxide hits 70 ppm and keeps rising, occupants may notice an increase in headaches, fatigue and nausea. Levels between 150 and 200 ppm can cause unconsciousness and disorientation and eventually become fatal.
  • Accuracy should be top priority when you’re comparing carbon monoxide detectors. One way to measure accuracy is to check a unit’s sensitivity. The Kidde Nighthawk Carbon Monoxide Detector can sense levels as low as 11 ppm but will only alert when the level gets dangerous. The First Alert Carbon Monoxide Alarm uses electrochemical sensors that can find both low and carbon monoxide levels.
  • Before you start shopping, determine exactly what type of danger detection you need. The Nest Protect Smoke & Carbon Monoxide Detector is a smoke and carbon monoxide detector in one. The unit combines both photoelectric and ionization sensors to monitor for fires. Those same sensors can also keep an eye out for signs of electrochemical carbon monoxide. Most other carbon monoxide detectors only handle CO detection, which means you’ll need separate smoke detectors. However, if you’re in the market for a new smoke detector as well, consider the First Alert Carbon Monoxide Alarm, which connects to other First Alert alarms to provide you with full-house protection.
  • With most CO detectors, you’ll only know once levels reach a certain threshold. However, both the Kidde Nighthawk Carbon Monoxide Alarm and the Alert Plus Carbon Monoxide Alarm show your current levels on an LCD display. The Alert Plus Carbon Monoxide Alarm Detector will begin issuing alerts within 60 to 90 minutes once you reach 50 ppm. If you hit 100 ppm, an alert will sound within 10 to 40 minutes, and 300 ppm sets off an alarm within three minutes.
  • If you do see an alert, it can help to know which part of your house the problem area is. The First Alert Carbon Monoxide Alarm lets you know where the threat is so that you can take action to fix it.
  • In addition to voice alerts to warn you of the danger, Nest Protect Smoke & Carbon Monoxide Detector has an LED that changes colors at varying levels. If you have low levels of smoke or carbon monoxide, you’ll get a yellow light while red light signals that you should exit the building immediately. The Alert Plus Carbon Monoxide Alarm also has a bright LED light.
  • When an alarm goes off, it’s important to have an alert at a volume audible to your entire household. The National Fire Protection Association recommends volume levels of at least 75 decibels. Both the Kidde Nighthawk Carbon Monoxide Alarm and First Alert Carbon Monoxide Alarm include alarms that are 85 decibels.
  • Another benefit of the Nest Protect Smoke & Carbon Monoxide Detector is that it connects to a smartphone app. This means you can log in and check your home’s levels even when you’re away.
  • One bonus feature on the Nest Protect Smoke & Carbon Monoxide Detector is that if you do need to exit, the alarm lights up the area to help you find your way out in the dark. It can also be linked up to the smart bulbs you have in your home to provide a visual alert when it’s time to evacuate.
  • You have two choices in how your carbon monoxide detector is powered. The Kidde Nighthawk Carbon Monoxide Alarm is a plug-in detector that runs off your home’s electricity. It also has a battery backup for those power outages. The First Alert Carbon Monoxide Alarm and Alert Plus Carbon Monoxide Alarm Detector are both battery-powered, so you’ll need to make sure you keep the batteries changed. The Nest Protect Smoke & Carbon Monoxide Detector is available in both wired and battery-powered versions.