Best X Sense Warning Alarms in 2026

Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide

85-decibel alarm & LED warning indicators alert you to various status: green = normal operation, amber = operating error, and red = smoke, fire or carbon monoxide event

Battery operated to provide reliable detection, even during power outages; two AA batteries included

UL Certified with a 10-year limited warranty on alarm

Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide

85-decibel alarm & LED warning indicators alert you to various status: green = normal operation, amber = operating error, and red = smoke, fire or carbon monoxide event

Battery operated to provide reliable detection, even during power outages; two AA batteries included

UL Certified with a 10-year limited warranty on alarm

Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide

85-decibel alarm & LED warning indicators alert you to various status: green = normal operation, amber = operating error, and red = smoke, fire or carbon monoxide event

Battery operated to provide reliable detection, even during power outages; two AA batteries included

UL Certified with a 10-year limited warranty on alarm

Test-Hush Feature - silences the unit for approximately 9 minutes; tamper-resistant technology deters removal of the unit from the wall or ceiling

UL Certified, 10-year limited warranty

Interconnects: Up to 24 Kidde devices (of which 18 can be initiating)

Meets safety standards set by Underwriters Laboratories (UL) and interconnects with other KN-COSM-IBA models

120V AC, All Kidde brand hard wired smoke alarms are interconnectable with the KN-COSM-IBA

Loud pulsing alarm that will sound to alert you to a potential problem

Low battery warning feature indicates when the battery needs replacement

UL Certified, 5-year Limited Warranty

Two alarms in one detects carbon monoxide and explosive gas

Three convenient mounting options

Digital display and peak level button displays the peak CO level recorded by the alarm since it was last reset

Battery backup 9 volt battery included

Kidde’s carbon monoxide alarms meet the requirements of Underwriters Laboratories (UL), an independent facility that tests products for compliance with widely-accepted safety standards

Photoelectric smoke detector senses visible fire particles and electrochemical CO detector provides accurate readings

UL Certified, 10-year limited warranty

Will interconnect with up to 24 other devices including smoke, CO and heat alarms

Photoelectric smoke detector senses visible fire particles and electrochemical CO detector provides accurate readings

UL Certified, 10-year limited warranty

Will interconnect with up to 24 other devices including smoke, CO and heat alarms

Package contains six smoke and carbon monoxide detector combo units

Product 1: Whole home family protection - place 1 carbon monoxide detector on each level of your home & in your bedroom to protect from poisonous gases

Product 2: Ionization sensing technology - hardwired smoke detector detects invisible fire particles, 85 decibel alarm alerts of fire

Product 2: Protects during a power failure - smoke alarm operates on one, 9-volt battery in the back of the unit

Product 2: Whole home family protection - place 1 fire detector on each level of your home & in your bedroom

Product 2: Test-Hush Feature - silences the unit for approximately 7 minutes

Low battery warning - One chirp followed by warning “low battery”. The red LED light will flash. This pattern will continue every minute for the first hour. After the first hour the red LED light will flash once every minute accompanied by the chirp sound. The “low battery” warning will only sound once every fifteen minutes. Voice Hush Indication: “Hush activated” and “Hush cancelled” voice announcement

Alarm memory - The green LED will blink once every 16 seconds to alert a user when the unit has alarmed for smoke or has detected a concentration of CO. If the alarm has detected a CO level of 100ppm or greater, when the test/reset button is pressed the unit will announce “CO previously detected”. If the alarm has detected abnormal levels of smoke since its last test, it will produce three rapid beeps.

AC-Wire with battery backup, An included 9V battery protects during short-term power outages

Front-loading battery with unique battery door design

Voice warning with green and red LEDs

Photoelectric smoke sensor – May detect visible fire particles associated with slow smoldering fires sooner than an ionization sensor.

Tamper resistant

Test-Hush Feature - silences the unit for approximately 9 minutes

UL Certified, 10-year limited warranty

Operates on a 10-year lithium battery, eliminating the need for battery replacement, while providing reliable detection during a power failure

Test-Hush Button makes testing the detector or silencing false alarms easy (false alarms may occur from routine cooking, shower steam, dust or humidity)

Interconnection capability: allows you to connect up to 24 Kidde alarms of this type, providing trusted detection throughout your home

UL Certified, 10-year limited manufacturer warranty

Enables extension of coverage & protection without any need for additional wiring

When one alarm sounds, they all do, providing an early warning against fire by dramatically increasing your ability to hear an alarm anywhere in your home, regardless of where the fire starts

Test-Hush button makes it easy to test the smoke detector and silence false alarms that occur from cooking or shower steam

Interconnection capability: allows you to connect up to 18 Kidde smoke, heat, or CO alarms, with the possibly it interconnect 6 strobe lights or relay modules

UL Certified, 10-year limited manufacturer warranty

Test-Hush Feature - silences the unit for approximately 9 minutes; tamper-resistant technology deters removal of the unit from the wall or ceiling

UL Certified, 10-year limited warranty

Operates on a 10-year lithium battery, eliminating the need for battery replacement, while providing reliable detection during a power failure

Combination fire alarm automatically activates when it is attached to the mounting bracket

Test-Hush Button makes testing the detector or silencing false alarms easy (false alarms may occur from routine cooking, shower steam, dust or humidity)

UL Certified, 10-year limited manufacturer warranty

Low Battery Warning – The unit warns of a low battery condition by announcing “low battery” and by initiating an alarm chirp and activating a flashing red LED.

Temperature Range:40˚F (4.4˚C) to 100˚F (37.8˚C)

Battery Powered – Provides protection even during power outages when many fire and carbon monoxide incidents occur

Battery Safeguard – The battery door will not close unless the batteries are properly installed.

Ionization Smoke Alarm Sensor

Easy to install alarm that is suitable for all liv-ing areas and has a 10-year life and a 7-year limited warranty.

The unit shall at a minimum meet the requirements of UL 2034, UL217, NFPA72, (chapter 11 2002 edition) The State of California Fire Marshall, NFPA101 (One and two family dwellings) Federal Housing Authority (FHA), Housing and Urban Development (HUD). It shall also include a 7-year manufacturer’s limited warranty

Low battery warning feature indicates when the battery needs replacement

UL Certified, 10-year limited warranty

Enables extension of coverage & protection without any need for additional wiring

Ambient Light Sensing feature establishes a day/night cycle and prevents late-night battery chirps in dark conditions

LED warning light indicators alert you to various statuses: a green light indicates the unit is in proper working operation, an amber light indicates an operating error, and a red light indicate smoke or fire

Interconnection capability: allows you to connect up to 24 Kidde smoke, heat, or CO alarms, with the possibly it interconnect 6 strobe lights or relay modules

UL Certified, 10-year limited manufacturer warranty

Compatible with RemoteLync Bridge - Connect to the Kidde app for additional features and benefits

The right alarm, the right location. - Each of the four smoke alarms includes features designed to address location-specific safety needs, such as an LED light in the hallway

End of Life Warning – Alarm chirps every 30 seconds to indicate the unit is in need of replacement

Enables extension of coverage & protection without any need for additional wiring

Ambient Light Sensing feature establishes a day/night cycle and prevents late-night battery chirps in dark conditions

LED warning light indicators alert you to various statuses: a green light indicates the unit is in proper working operation, an amber light indicates an operating error, and a red light indicate smoke or fire

Interconnection capability: allows you to connect up to 18 Kidde smoke, heat, or CO alarms, with the possibly it interconnect 6 strobe lights or relay modules

UL Certified, 10-year limited manufacturer warranty

Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide

85-decibel alarm & LED warning indicators alert you to various status: green = normal operation, amber = operating error, and red = smoke, fire or carbon monoxide event

Battery operated to provide reliable detection, even during power outages; two AA batteries included

UL Certified with a 10-year limited warranty on alarm

Compatible with Amazon Alexa, Google Home, iPhone, & Android smart devices

Indoor Air Quality Monitoring: monitors harmful chemicals known as Total Volatile Organic Compounds (TVOCs) that come from cleaning products & paint, also monitors humidity & mold risk

WiFi enabled technology allows notifications to be sent to your smartphone (as well as friends & family) in the event of a CO hazard in your home

Electrochemical sensor technology detects poisonous carbon monoxide gas inside your home

First UL listed carbon monoxide & indoor air quality monitoring device; 10-year limited manufacturer warranty on alarm - not a battery replacement claim

Product 1: Advanced technology – smoke and carbon monoxide detector combines ionization & electrochemical sensors to detect invisible fire particles & CO gas

Product 2: Ionization sensing technology may detect invisible fire particles, associated with flaming fires, quickly and sound an 85dB alarm

Product 2: Hardwired smoke detector with battery backup (included) ensures that you'll be alerted to a fire, even during a power outage

Product 2: Large base makes mounting easy, while a front battery pull lets you activate the smoke alarm without removing it from the mounting bracket

Product 2: Whole home family protection - place 1 fire alarm on each level of your home & in your bedroom; maximum of 24 Kidde devices can be interconnected

Product 1: Test-Hush Feature - silences the unit for approximately 8 minutes; tamper-resistant technology deters removal of the unit from the wall or ceiling

Product 2: Fire and CO detector in 1 unit with alert modes, LED lights, and voice alarm, that states, "Fire. Fire.", "Warning. Carbon Monoxide.", or "Low Battery."

Product 2: Ionization sensor technology - smoke detector detects invisible fire particles, 85 decibel alarm alerts of fire

Product 2: Protects during a power failure - combo smoke and CO alarm operates on 2-AA batteries

Product 2: Test-Hush Feature - silences the unit for approximately 8 minutes; tamper-resistant technology deters removal of the unit from the wall or ceiling

Compatible with Amazon Alexa, Google Home, iPhone, & Android smart devices

WiFi enabled technology allows notifications to be sent to your smartphone (as well as friends & family) in the event of a smoke or air quality hazard in your home

85-decibel alarm & LED warning indicators alert you to various status: green = normal operation, amber = operating error, and red = smoke, fire or carbon monoxide event

Photoelectric sensor technology detects visible fire particles associated with smoldering fires

First UL listed smoke & indoor air quality monitoring device; 10-year limited manufacturer warranty on alarm - not a battery replacement claim

Product 1: Hush feature silences nuisance or “false” alarms – with just the push of a button on the alarm itself

Product 2: Ionization sensing technology - hardwired smoke detector detects visible fire particles, 85 decibel alarm alerts of fire

Product 2: Protects during a power failure - smoke alarm operates on a 120V power source with 3V lithium battery backup

Product 2: Whole home family protection - place 1 fire detector on each level of your home & in your bedroom - maximum of 24 Kidde smoke or CO detectors can be interconnected in a multiple stations

Product 2: Test-Hush Feature - silences the unit for approximately 9 minutes. Alarm Memory Indicator

Product 1: Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide

Product 2: Heat detector alerts to temperatures rising above 135⁰ Fahrenheit & sounds an 85-decibel alarm to help protect your family

Product 2: Protects during a power failure - heat alarm operates on a 120V wired power source with 9V battery backup

Product 2: Quick-connect power harness makes installation fast and easy

Product 2: Test Button lets you check that the heat sensor’s electronic circuitry, horn, and battery are working

Combined Carbon Monoxide and Smoke Alarm – A single unit can be installed where previously, 2 were needed. Reduces installation time and helps to keep home décor attractive.