Last updated on March 7th, 2023 at 05:47 am
The capacity of a smoke and CO detector to detect carbon monoxide (CO) might be the difference between life and death.
Around 400 People die from unintentional CO poisoning each year, and nearly 100,000 visit emergency rooms, according to the Centers for Disease Control and Prevention.
Although most detectors have a similar appearance and are approved by organizations like Underwriters Laboratories (UL) or Intertek Electrical Testing Labs (ETL), their effectiveness may differ.
Some sensors are ineffective at detecting CO, and there are variations in how rapidly various models react to CO.
Knowing that such vital gadgets truly function is comforting since “I have never examined a model that failed our fire and smoke testing.”
Check out our ratings for smoke and carbon monoxide detectors to get a list of all the types we’ve evaluated. Moreover, read the purchasing advice to determine which sensors are best for your house.
To test how successfully detectors detect fire and smoke, we expose them to burning and smoldering flames in the laboratory.
It linked CO alarms to exact low CO levels (100 ppm, or parts per million) and high CO levels (400 ppm) to determine how precisely and rapidly they detect the deadly carbon monoxide.
These alarms respond as a group when any one of them is activated.
Also, we examine the accuracy of the CO levels that stand-alone CO detectors either show on their displays or read aloud through voice messages.
Detectors typically run on batteries, are hardwired, or are connected to an outlet. Remove the sensors in your house from their mounts to identify the kind you need.
- Detectors that run on batteries are cordless and portable.
- They usually use AA or 9-volt replacement or sealed lithium batteries with a 10-year shelf life to power them.
- Hardwired detectors need specialized power wiring, often only present in newly constructed or remodeled residences.
- If the cables attached to your sensors reach into a wall or ceiling, you have hardwired detectors.
- Plug-in detectors are powered continuously by an outlet.
- Plug-in and hardwired detectors include an emergency battery that will take over in the case of a power failure. Every year, backup batteries must be replenished.
In alphabetical order, here are the best choices for stand-alone smoke detectors, stand-alone CO detectors, combination smoke-CO detectors, and intelligent smoke-CO detectors that can send alerts to your smartphone.
Each type of detector has both hardwired and battery-powered options.
Best Smoke Detectors That Are Hardwired
First Warning 3120B
Walmart has $32.81 in stock.
The First Alert 3120B is a dual-sensor smoke detector with an ionization sensor for flame detection and a photoelectric sensor for smoke-producing fires.
Our First Alert performs very well in both our raging fire and smoldering fire tests because of the usage of both kinds of sensors.
It has a hush button to turn off bothersome alerts and is hardwired with a battery backup, making it a suitable choice for newer or renovated houses with wiring for detectors.
If one goes out, they warn you of danger, even if you’re in a different room or level from the fire. It can be linked to other detectors in this way.
Kidde PI2010

Stocked at $33.52 Amazon Shop
The Kidde PI2010 is another standout performer in our testing, receiving the best marks achievable in both the raging fire and smoldering fire tests.
This battery-operated, dual-sensor alarm is hardwired and can link to additional suitable detectors. It also has a quiet button. Consult Kidde to see whether other models are compatible with this one.
Read: Cheers to St. Patrick’s Day with These Deals and Discounts
Best Smoke Detectors for Batteries
Early Warning SA320CN

$41.92 Walmart & Amazon Visit Offers
The First Alert SA320CN scored well in the burning and smoldering fire tests, making it one of our rankings’ top battery-powered dual-sensor detectors.
It has a hush button and requires two AA batteries, but it can’t communicate with other alarms to set off all of them simultaneously in the case of a fire.
SA3210 First Alert Maximum Protection (Battery)

57.94 Amazon & Walmart Store $92.77
The Maximum Protection SA3210 from First Alert passed the burning and smoldering fire tests with flying colors.
The SA3210 has a hush button similar to the SA320CN; instead of using two AA batteries, the SA3210 uses a 10-year lithium battery. Moreover, it cannot communicate with other smoke detectors.
PI9010 Kidde

See Deals Amazon Store
The Kidde PI9010 is another excellent option for a battery-powered detector. This perfect detector performs well in our testing for burning and smoldering flames.
While it has a quiet button and requires a single 9-volt battery, it cannot communicate with other detectors.
AMIB3051SC by Universal Security Instruments

See Deals Amazon Store
One of the first smoke detectors created to the most recent UL 217 standard for smoke alarms, the Universal Security Instruments AMIB3051SC, makes smoke detectors better at eliminating false alerts caused by cooking.
With a built-in 10-year alkaline battery, this device performs well in our tests for burning and smoldering flames. It also has a quiet button; however, it cannot communicate with other detectors.
Read: Upgrade Your Tech Game with These Apple Watch Deals
Best-Hardwired Carbon Monoxide Detector
Kidde KN-COSM-IBA

In stock Amazon Store $47.99 & Availability $48.00 Walmart Store
The Kidde KN-COSM-IBA CO detector that is hardwired works well. It scores well in our low-CO-level test and for the precision of its CO-level display. Our high-CO-level test scores are almost at the top of the scale.
Peak memory, a feature of the model that allows it to record the highest CO levels it can detect, helps check if there has been an issue after being away from home for a while.
It can also link to other compatible alarms and has a battery backup.
Best Carbon Monoxide Detector for Plug-Ins
First Warning CO615

In Stock $36.04 Walmart & $50.86 Amazon Shop
The First Alert CO615 is one of the few plug-in CO detectors we tested, and it did better than its hardwired and battery-powered counterparts.
It got an excellent grade for quickly detecting high and low CO levels and a good quality for how accurate its CO level display was.
Thanks to its battery backup and peak memory functions, you can check to see whether CO levels have been high after being away for a while.
Best Carbon Monoxide Detector that Runs on Batteries
OneLink First Alert SCO501CN

$38.83 Available on Amazon for $57.26 & Walmart
Have a look at the First Alert OneLink SCO501CN if you need a battery-operated CO detector. It performs well in identifying high and low CO levels and the precision of its CO readings.
An 85-decibel siren and voice alarm (with 11 customizable locations) alert people to the location and nature of the development when the alarm detects CO.
This type offers wireless interconnection with other First Alert-enabled alarms in addition to voice alerts.
The notice contains a peak memory function that records the highest CO measurement to determine if there was an issue while you were away from home.
Read: 24 Amazing Fashion Deals at Amazon Just in Time for the Weekend!
Best Smoke/Carbon Monoxide Combination Detectors
AMICH3511SC by Universal Security Instruments

Stocked at $56.95 Amazon Prime & at Walmart $61.90
The best option for a hardwired combination detector is the Universal Security Instruments AMICH3511SC.
It performs well in our testing for low CO levels, smoldering fire, and burning fire. It received a passing grade for identifying elevated CO levels.
It has a sealed battery that should last for ten years and is certified to guard against smoke, fire, and carbon monoxide.
MIC3510SB by Universal Security Instruments

Stocked at $56.95 Amazon Prime & Walmart $61.90
One of the rare combination detectors, the Universal Security Instruments MIC3510SB also features a CO sensor and both photoelectric and ionization sensors for smoldering and burning flames (most combo versions only have one of the two).
So far, our smoke and CO testing have shown that this USI detector is the only combo model to function satisfactorily.
This particular model contains a quiet button and a sealed 10-year battery. Yet, it is unable to link to other detectors.
Most Effective Smart Combination Detectors
First Alert Onelink Smart 1042135

Stocked at $89.75 Amazon Prime & Walmart $100.87
Check out the First Alert Onelink Smart 1042135 for a bright CO and smoke detector that connects to WiFi immediately.
It provides excellent results for this model, except for raging flames, which fail due to a lack of an ionization sensor.
If you buy this smoke detector, consider purchasing a battery-operated ionization smoke detector, such as the Kidde RF-SM-DC.
This First Alert is available in battery-powered and hardwired variants, can link to additional compatible sensors, and supports Apple HomeKit/Siri and Amazon Alexa for voice control and app access.
First Alert ZCOMBO

See Deals Amazon Store
The First Alert ZCOMBO is an advanced smoke, and CO detector approved with Ring’s home security system. You can control the detector using the Ring app on your phone.
It excelled in our smoldering flames test and detected low CO levels precisely and rapidly. Yet when challenged to find blazing flames, it did miserably. There are batteries within the First Alert ZCOMBO.
Read: Top Deals Under $100 for Smart Shoppers
Google Nest Protect: Carbon Monoxide + Smoke

Available $105.99 Amazon & Available $117.00 Walmart
Another WiFi-enabled smoke-CO detector that performs well in our testing is Google Nest Protect.
It performs well in our testing for detecting low CO levels and smoldering fires and even earns a good grade for detecting high CO levels.
Yet it fails our blazing fire test, much as the First Alert Onelink. If you buy this smoke detector, consider purchasing a battery-operated ionization smoke detector, such as the Kidde RF-SM-DC.