Kidde Hardwired Smoke & Carbon Monoxide Detector — Battery Backup, Voice Alerts, Interconnectable

The Kidde KN-COSM-IBA is a hardwired combination smoke and carbon monoxide alarm with battery backup, voice alerts, and interconnect capability for whole-home protection.

This dual-sensor alarm combines an ionization smoke detector with an electrochemical carbon monoxide sensor into one compact unit designed for permanent 120VAC installation with 2-AA battery backup. It provides clear LED status indicators, spoken warnings, a hush feature for nuisance alarms, and the ability to interconnect with other Kidde devices so every alarm in the home sounds when one detects danger. Certified to major UL and NFPA standards, it’s built for long-term, code-conscious installations and comes with a 10-year limited warranty.

How does this detector alert my household to smoke or carbon monoxide?

When smoke or dangerous CO concentrations are detected, the alarm emits loud audible signals plus a voice announcement that distinguishes the hazard. LED indicators provide visual confirmation—red for alarm conditions and green for hush status—so occupants quickly know what’s happening.

• 85 dB audible alarm for immediate attention
• Voice messages: “Fire,” “Carbon Monoxide,” or “Low Battery”
• Red LED flashes during alarm; green LED flashes during Hush
• Battery backup ensures alerts during power outages

What technologies does the unit use to detect hazards?

This combination unit uses an ionization chamber to sense invisible particles common to fast-flaming fires and a patented electrochemical sensor for accurate CO detection. The two-sensor approach increases the chance of early detection across different fire types and continuous CO monitoring.

• Ionization sensing for quick detection of flaming fires
• Electrochemical CO sensor for reliable carbon monoxide readings
• Continuous monitoring even when AC power is lost (battery backup)
• Meets UL 217 and UL 2034 standards

Can multiple Kidde alarms be linked together and how many?

You can interconnect Kidde alarms to form a coordinated notification network throughout a home. The KN-COSM-IBA supports up to 24 Kidde devices wired together, while observing NFPA limits for initiating devices to maintain code compliance.

• Interconnect up to 24 Kidde devices total
• NFP A initiation limits: up to 18 initiating devices (max 12 smoke alarms)
• Compatible with other KN-COSM-IBA units and many Kidde wired systems
• Can still support auxiliary strobes or relay modules in the network

How do I manage false alarms and maintenance with this detector?

The unit includes a Test-Hush feature to temporarily silence nuisance alarms and tamper-resistant design to discourage removal. Regular testing and following replacement guidelines for CO sensors keep the system reliable without overreacting to common household activities.

• Hush silences the alarm for about 9 minutes to limit nuisance triggers
• Tamper-resistant locking reduces accidental removal
• Perform regular weekly tests and replace CO alarms per manufacturer guidance
• Locate alarms at least 15 feet from cooking/heating appliances to avoid false alarms

Who this product is for: Homeowners, property managers, and builders who want a code-compliant, dual-function alarm that combines ionization smoke detection and electrochemical CO sensing in one hardwired unit. It’s especially well suited for homes that need interconnected alarm networks, require battery backup for power outages, and prefer voice alerts for unambiguous hazard identification. Install in sleeping areas, on each floor, and wherever local codes require combination detection for a practical single-device safety solution.