Having the most reliable smoke and carbon dioxide detector in your house is like you are proactively improving the protection of yourself and your family against fires. Therefore, it’s worth considering carefully.
Here are the most reliable smoke and carbon monoxide detectors you can buy in 2025:
- Long Lasting (Ionization Detector): FIRST ALERT BRK SC9120B
- Best For Dining Room (Ionization Detector): Kidde KN-COSM-IBA
- Easy To Install (Ionization Detector): Kidde i12010SCO
- Durable (Photoelectric Detector): X-Sense XP01-W
- Budget Option (Photoelectric Detector): Lecoolife GS528A
- Best For Consistent Performance (Photoelectric Detector): X-Sense SC01
| 6 Most Reliable Smoke And Carbon Monoxide Detectors | ||
|---|---|---|
Long Lasting | FIRST ALERT BRK SC9120B
| |
Best For Dining Room | Kidde KN-COSM-IBA
| |
Easy To Install | Kidde i12010SCO
| |
Durable | X-Sense XP01-W
| |
Budget Option | Lecoolife GS528A
| |
Best For Consistent Performance | X-Sense SC01
| |
Long Lasting: FIRST ALERT BRK SC9120B
- Able to work consistently during shortages – include high-quality battery backup
- Safe and dependable – meet UL standards & made by a well-known manufacturer
- Convenient – compatibility with First Alert or BRK detectors
- Battery replacement is a big struggling
- The light indicator isn’t bright enough
If you’re looking for the cheapest ionization detector that still works reliably even during a power outage, we think this model should be your best bet.
It comes with high-quality alkaline batteries, with a max lifespan of up to 1.5 years, that can back up for sudden shortage situations. While most other counterparts’ batteries only last around 3-6 months, this is the longest-lasting option.
Regardless, it is made by one of the oldest brands of in-home safety and has been tested thoroughly to achieve UL certification.
It highlights an electrochemical carbon monoxide sensing technology – that will trigger an 85-decibel siren once detecting smoke or CO.
If other rooms of your home are already equipped with First Alert or BRK detectors, this one is compatible with them.
| FIRST ALERT BRK SC9120B Specifications | |
|---|---|
Size | 5.6 x 5.6 x 1.9 inches |
Alarm Noise Level | 85 decibels |
CO Alarm Sensitivity & Time | 70 ppm/ 60 - 240 min. 150 ppm/ 10 - 50 min 400 ppm/ 4 - 15 min |
Highlight Features | include high-quality battery backup meet UL standards & made by a well-known manufacturer compatibility with First Alert or BRK detectors |
The FIRST ALERT BRK SC9120B doesn’t require as much battery replacement times as its competing models plus it can work reliably during power outages, thanks to the premium battery backup included.
Best For Dining Room: Kidde KN-COSM-IBA
- Ideal for kitchen – feature humidity range of 10%-90% & temperature range of 60-100 degrees F
- Provide extra action time – voice alarm & siren
- Ensure it works properly after installation - battery safeguard
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Made to achieve all UL safety standards, the Kidde KN-COSM-IBA is another dependable smoke and CO detector we’d like to recommend to you.
It stands out for featuring ultra-wide humidity ranges of 10% to 90% (while most others’ just up to 85%). Combining the temperature range of 60-100 degrees F, it becomes a great choice for those spaces that are usually hot and highly humid, such as the kitchen and dining room.
One of our most favorite KN-COSM-IBA features is its voice alarm once the device detects a deadly CO concentration in the air before the siren is shrieking overhead.
You can turn this function off by just a gentle press on its test-reset button.
If you have more than one KN-COSM-IBA installed in your home, they are easily compatible together. During installation, the best part is you take no risks of forgetting to insert batteries or inserting them improperly, thanks to the battery safeguard.
| Kidde KN-COSM-IBA Specifications | |
|---|---|
Size | 2 x 6 x 6 inches |
Temperature Range | 60-100 degrees F |
Humidity | 10%-95% |
Alarm Noise Level | 85 dB |
CO Alarm Sensitivity & Time | 100ppm or higher/ approximately 9 minutes |
Highlight Features | feature humidity range of 10%-90% & temperature range of 60-100 degrees F voice alarm & siren battery safeguard |
The Kidde KN-COSM-IBA is specifically built with ultra-wide humidity and temperature range, making it a nice pick for those highly humid areas, like the dining room.
Easy To Install: Kidde i12010SCO
- Easy to install – including all the mounting hardware, wiring harness, and mounting bracket in the package
- Able to detect unseen carbon monoxide and fire molecules - Intelligent technology
- None
The Kidde i12010SCO is probably the easiest-to-install ionization detector that we have found.
Along with high-quality materials, it comes with all the mounting hardware plus wiring harness and mounting bracket, making installation effortless. The clear instructions are a nice added bonus.
Speaking of functionality, the Kidde i12010SCO stands out for its capability of detecting unseen CO gas and fire particles.
It also allows you to interlink 24 Kidde devices in a network for all-in-one-place control. The battery is proven to last up to 10 years and you’ll know when to replace it thanks to the light indicator. Very convenient!
| Kidde i12010SCO Specifications | |
|---|---|
Size | 5.5 x 1.5 x 5.5 inches |
Temperature Range | 40-100 Degrees Fahrenheit |
Humidity | 10% to 95% |
Alarm Noise Level | 85 dB |
Highlight Features | including all the mounting hardware, wiring harness, and mounting bracket in the package Intelligent technology |
The Kidde i12010SCO comes with everything required for the installation, making it very easy to install.
Durable: X-Sense XP01-W
- Durable - fire-retardant ABS housing
- Convenient - extra-large button
- The battery can’t be removed or replaced
The X-Sense XP01-W is built to last.
It is wrapped around by fire-retardant ABS housing, and supported by the manufacturer's 5-year warranty and 60-day money-back guarantee.
Similar to other brands, this smoke and CO detector is easily interconnected with other X-Sense devices. The connection is also simple and fast.
One small feature that puts a huge impact on your convenience is the extra-large button. Instead of you having to climb a ladder to press the button, just use a broom handle.
Note: Each works well in a room from 215 to 430 square feet in size.
| X-Sense XP01-W Specifications | |
|---|---|
Size | 5.3 x 5.3 x 1.7 inches |
Temperature Range | 40°F to 100°F |
Highlight Features | fire-retardant ABS housing extra-large button |
We’re fans of the X-Sense XP01-W for its unparalleled durability
Budget Option: Lecoolife GS528A
- Affordable yet quality - slow- and fast-burning fires, a 10-year battery, ABS plastic housing, and good warranty
- Showing the current CO concentration in the air - an LCD display screen
- Space-saving – compact size
- The light indicators are too bright for bedroom
The Lecoolife GS528A perfectly neutralizes between price and functionality.
It has features found in higher-end smoke and CO detectors like the capability of detecting both slow- and fast-burning fires, a 10-year battery, ABS plastic housing, and good warranty.
It even features an LCD display screen to show you the current CO concentration in the ambience and doesn't require hardwired installation at all.
At such a low price, the unit obviously has to scarify some features like the less various light indicators. Some of our testers also claim that the light indicators are too bright at night, especially in a small room - which might cause annoyance while you're sleeping.
| Lecoolife GS528A Specifications | |
|---|---|
Size | 5.35 x 5.35 x 4.17 inches |
Alarm Noise Level | > 85dB(A) |
CO Alarm Sensitivity & Time | 30-999 ppm/flash red 4 times every 5.8 seconds |
Highlight Features | an LCD display screen compact size |
The Lecoolife GS528A is a high-value option in a world of expensive smoke and carbon monoxide detectors. It’s our favorite pick for budget option.
Best For Consistent Performance: X-Sense SC01
- Consistent performance – 10-year sensors & 10-year battery
- Able to check the unit in low light conditions – LCD display with backlit
- Easily inspect different indicators at one spot
- Wish the numbers on the display screen were larger
- The test/silence button could be bigger
This set of 5 packs really comes in handy to provide full protection for a large house.
They all are accurate, easy to install, easy to interlink, and meet all the safety standards of UL 2034 and UL 217. Besides, not only the battery but also the sensors are guaranteed to last 10 years, which ensures the most consistent performance.
The X-Sense SC01 has a backlit screen display where you can easily check the current CO concentrati
| X-Sense SC01 Specifications | |
|---|---|
Size | 5.7 x 5.7 x 2 inches |
Temperature Range | 40 °F to 100 °F. |
Alarm Noise Level | over 85 dB |
CO Alarm Sensitivity & Time | 30-999 ppm & flash red 4 times every 5.8 seconds |
Highlight Features | 10-year sensors & 10-year battery LCD display with backlit |
the working status of the unit, and the remaining battery life in any condition, even in the darkness.
The X-Sense SC01’s consistent performance makes it our favorite pick for this review list.
How To Choose The Most Reliable Smoke And Carbon Monoxide Detector?
Types Of Smoke Detectors
As fires burn differently – some are fast to the flame while others are slower. Therefore, there are three main types of smoke detectors:
Photoelectric smoke detectors
Designed with higher sensitivity to detect slow-flame fires faster than the ionization ones. However, they’re inferior to their counterparts in detecting fast-flame fires. They work best in the kitchen because they make fewer false alarms from burnt food.
Ionization smoke detectors
This type is completely in contrast to the photoelectric smoke detectors, which means it works best in detecting fast-flame fires and bad at smothering fires.
Dual-sensor smoke detectors
Easy to guess that this smoke detector type combines those two above, which means it brings the highest protection for you against both smothering and fast-flaming fires.
Besides, this one reduces the hassles of installing two devices in your house.
CO Alarm
This function helps you know the exact, up-to-date buildup of carbon monoxide in your house and will sound after a certain amount of time it continuously detects a dangerous CO level in the air.
The sensitivity of CO alarm is measured in PPM (parts per million) and the response time is in minutes or hours.
The response time is varied depending on the CO level. For example:
CO levels (PPM) | CO alarm response time |
400 | 4-15 hours |
150 | 10-50 minutes |
70 | 1-4 hours |
50 | 8 hours |
40 | 10 hours |
The higher the CO levels, the more dangerous, therefore, the shorter the CO alarm response time. A trick to ensure your CO alarms are reliable is to look for the UL certification on their label.
Alarm Noise Level
Another worth-considering feature when looking for the most reliable smoke and CO detector is the alarm noise level. It should be loud enough to warn you about the danger for quick action but should not be too loud to damage your ears.
The recommended alarm noise level for smoke and CO detectors should be at 85 decibels.
Besides, you should consider the voice alarm for extra action time before the siren is activated.
Which Brands Make The Most Reliable Smoke And Carbon Monoxide Detector?
FIRST ALERT
FIRST ALERT is a 1964-founded company specializing in manufacturing smoke and CO detectors.
They’re the first to the retail market with a battery-operated smoke alarm and then, dual ionization/photoelectric alarm. Their products are always UL listed and give a great blend of dedication, trustworthiness, quality, and reliability.
Kidde
Have you heard about Carrier Global? Kidde is a brand and a division of theirs, dedicated to producing and distributing suppression and fire detection equipment. It was started in 1917 and has now been the US’s biggest brand in fire safety products and smoke alarms.
X-sense
X-sense is a young yet reliable global leader in smoke and CO detectors. Though they were established in 2014, their products have been widely sold to over 48 countries in the world and received much positive feedback from customers.
FAQs
Is Kidde or First Alert better?
Kidde is easier to install and budget-friendly while First Alert is superior in features, especially the function of verbal warning of the threat built in their alarm system.
Are combo smoke CO detectors good?
Yes, they are. Using photoelectric and ionization technology, they can detect both slow- and fast-flaming fires for extra safety and protection
Which is better ionization or photoelectric smoke detector?
We would say each type of smoke detector delivers specific strengths and weaknesses. Photoelectric smoke detectors give a faster response to the smoldering fires while ionization ones can detect fast-flaming fires more quickly.
Is 30 ppm carbon monoxide dangerous?
No, it isn’t. 30ppm carbon monoxide is still ranked in the low level. The dangerous level is more than 101ppm
What do 4 beeps on a carbon monoxide detector mean?
It means “Emergency” – the level of CO in the area is dangerous. What you should do is to move to fresh air and call 911.
Conclusion
During our testing, we got surprised repeatedly by how practical and useful these products proved to be. Hopefully, our article comes in handy for you in determining the most reliable smoke and carbon dioxide detector for your budget, needs, and situations. Thanks for reading!
