Kidde Hardwired Carbon Monoxide Detector with Battery Backup
- 120V hardwired with 9-volt alkaline battery backup included
- 85-decibel alarm with red LED on CO detection
- Up to 24 Kidde devices interconnected, plus 6 strobes or relay modules
- Carbon monoxide only, electrochemical sensor
- 3 LED indicators, green for power and red for alarm
- Meets UL 2034, tamper-resistant
- 10-year limited warranty on the alarm per bullets; spec sheet says 5 year
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A straightforward wired CO alarm for homes already on a Kidde interconnect network, with a battery that covers power cuts. It senses carbon monoxide only, and the listing gives conflicting warranty lengths.
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ASIN: B0009A138ECategory: Carbon Monoxide Detectors
Overview
Not a smoke alarm and not a plug-in unit, the Kidde KN-COB-IC is a hardwired carbon monoxide detector with an electrochemical sensor and a backup battery that takes over during a power failure. It joins a wired network of Kidde alarms and sounds its own pattern for carbon monoxide.
Linking into an existing Kidde wiring network lets it share alarms with smoke and heat units, and it sounds a different pattern for fire than for carbon monoxide. Installation needs a wired circuit, so it suits a replacement or new build more than a quick upgrade. Expect a separate smoke alarm for fire coverage.
Who it's for
Hallways and sleeping areas wired for alarms, especially where Kidde smoke units already run on one network, are where it belongs. Households without alarm wiring are better served by a plug-in or battery model.
Pros and cons
- Battery backup covers power failures
- Links with up to 24 Kidde devices
- Distinct alarm pattern for CO versus smoke
- Loud 85 dB alarm with red LED
- Warranty listed as both 10 and 5 years
- Requires hardwired 120V installation
- Interconnect limited to Kidde devices
- Senses CO only, not smoke
Performance notes
Detection relies on an electrochemical cell that responds to carbon monoxide, and placement decides how quickly gas reaches it. Kidde advises mounting it well away from cooking and heating appliances to cut false alarms, and on every floor and near bedrooms so the alarm is heard. When mains power drops the backup battery carries on monitoring, so coverage does not lapse during an outage.
Specifications
| Brand | Kidde |
|---|---|
| Dimensions & fit | |
| Item Weight | 0.8 pounds |
| Item Dimensions D X W X H | 2.2 × 6 × 5.9 inches |
| Capacity & performance | |
| Upper Temperature Rating | 100 °F |
| Power & efficiency | |
| Power Source | Corded Electric |
| Construction & materials | |
| Enclosure Material | Plastic |
| Color | No Finish |
| Compatibility & installation | |
| Compatible Devices | Up To 24 Kidde Devices |
| Included components | |
| Unit Count | 1 |
| Warranty & support | |
| Manufacturer Warranty Description | 5 Year Limited |
| Other details | |
| Sensor Type | Electrochemical |
| Alarm | fire safety, electrochemical, wired, tamper-resistant |
| Operating Humidity | 10% to 85% relative humidity, non-condensing |
| Number Of Items | 1 |
| Product Style | Hardwired Carbon Monoxide Detector |
| Mfr Part Number | 21006406 |
| Builtin Media | Kidde Hardwire Carbon Monoxide Detector Alarm With Battery Backup, Interconnectable / Model KN-COB-IC |
| Item Type Name | Carbon Monoxide Detector |
Frequently asked questions
What comes in the box with the Kidde KN-COB-IC?
The listing confirms the alarm and its 9-volt alkaline backup battery. It does not itemize a mounting plate or wiring connector, so check the package before installation day.
Does the Kidde KN-COB-IC detect smoke?
No. It senses carbon monoxide only. When interconnected with a Kidde smoke alarm that is in alarm mode, it sounds a different pattern from its CO alarm.
Is the KN-COB-IC warranty 10 years or 5 years?
The bullets and description state a 10-year limited warranty on the alarm, starting when it is powered on, while the spec sheet lists 5 year limited. Kidde also advises replacing CO alarms every 5 to 7 years.
Where should I install the Kidde KN-COB-IC?
Kidde advises at least one CO alarm on every floor and in sleeping areas, at least 15 feet from cooking or heating appliances to prevent false alarms.
What happens to the KN-COB-IC during a power outage?
The 9-volt battery backup in the back of the unit continues monitoring for carbon monoxide.