Kidde 900-CUAR Hardwired Smoke and CO Alarm — Interconnectable

The Kidde 900-CUAR Hardwired Smoke and CO Alarm provides combination smoke and carbon monoxide detection in a single hardwired unit with battery backup — the installation format required by building codes in new residential construction and preferred for alarm replacement in structures with existing hardwired systems. Kidde is one of the foremost names in fire and CO safety, and the 900-CUAR delivers dual-hazard protection that meets NFPA 72 and UL listing requirements for both smoke and CO in residential and light commercial installations where professional-grade reliability is non-negotiable.

Key Features

• Combination smoke and carbon monoxide detection — single device covers both hazards
• Hardwired AC power with battery backup for continuous protection through power outages
• Interconnectable with other Kidde hardwired alarms — all units alarm when one detects danger
• UL 217 (smoke) and UL 2034 (CO) listed for residential code compliance
• NFPA 72 compliant for new construction and replacement installations
• Audible alarm with distinct patterns for smoke vs. CO emergencies
• Battery backup maintains function during AC power interruption
• Test/reset button for routine testing and alarm silence
• End-of-life signal notifies when unit replacement is required

Specifications

Detailed Description

The Kidde 900-CUAR is engineered for the professional installation market — new construction, hardwired replacement, and renovations where building codes require AC-powered alarms. As a combination unit, it satisfies both smoke and CO detection requirements with a single device per location, which reduces total device count, simplifies installation, and provides a cleaner ceiling-plane aesthetic compared to side-by-side separate units.

Hardwired installation ties the alarm directly to the structure's AC electrical system. Unlike battery-only units, hardwired alarms are not subject to battery removal by occupants or depletion without replacement. The battery backup is not the primary power source — it is a failsafe that ensures the alarm remains operational during power outages, exactly the conditions under which CO risk may increase if occupants resort to generators, portable heaters, or other combustion equipment. This backup power distinction is why building codes in new construction require hardwired alarms rather than simply permitting battery units.

CO detection adds a layer of protection that smoke detection alone cannot provide. Carbon monoxide is colorless and odorless — completely undetectable by human senses until symptoms of poisoning appear, at which point a victim may already be too impaired to respond. The 900-CUAR's CO sensor continuously monitors for CO accumulation, alarming at concentration levels specified by UL 2034 to provide warning before incapacitation occurs. Common residential CO sources include gas furnaces, water heaters, attached garage vehicles, and wood-burning equipment — all present in structures where the 900-CUAR will be installed.

Interconnect capability is one of the key code compliance advantages of hardwired alarms. NFPA 72 requires that all smoke alarms in a dwelling be interconnected so that when any single alarm activates, all alarms in the structure sound. The 900-CUAR interconnects with compatible Kidde hardwired units, ensuring that an alarm triggered by smoke in a basement utility room simultaneously activates alarms in every bedroom in the structure. Proper interconnection is one of the most cited deficiencies in residential fire alarm inspections.

Installation requires connection to a 120V AC circuit with neutral wire. In new construction, this circuit is provided during rough-in electrical work. For replacement of existing hardwired alarms, the 900-CUAR connects to existing wiring, typically with the same connector as other Kidde products — simplifying like-for-like replacement across a building's alarm network. As with any hardwired electrical work, compliance with local electrical codes and permitting requirements applies.

Compliance and Standards

• UL 217 — UL standard for single and multiple station smoke alarms; required for code-compliant residential installation
• UL 2034 — UL standard for single and multiple station carbon monoxide alarms; required where CO alarms are mandated by code
• NFPA 72 — National Fire Alarm and Signaling Code; governs placement, installation, and interconnection of residential smoke and CO alarms
• Meets requirements for new construction hardwired alarm provisions under International Residential Code (IRC)

Real-World Benefits

Contractors gain a single SKU that satisfies both smoke and CO detection requirements per location, reducing materials on new construction projects. Property owners benefit from the maintenance advantage of hardwired power — no battery swaps for the primary power source. Interconnect capability ensures the whole-structure alarm coverage required by NFPA 72 without additional wiring beyond the standard interconnect loop.

Applications and Use Cases

• New residential construction requiring code-compliant hardwired smoke and CO alarms
• Hardwired alarm replacement in existing homes with 120V AC wiring
• Multi-family residential buildings requiring interconnected alarm systems
• Residential remodels triggering code upgrade requirements
• Rental properties in jurisdictions requiring hardwired alarms in bedroom locations
• Light commercial occupancies with residential-equivalent code requirements

Related Products

• Fire Safety — Full Collection
• Kidde Photoelectric Smoke and CO Detector with Voice Alerts

Frequently Asked Questions

Does the Kidde 900-CUAR require a licensed electrician to install?

In new construction, connecting to new circuits requires a licensed electrician in most jurisdictions. Replacing an existing hardwired alarm on an existing circuit is generally within the scope of a knowledgeable DIYer, but always check local electrical code and permitting requirements before doing your own electrical work.

What type of smoke detection does the 900-CUAR use?

Consult the Kidde product data sheet for the specific sensing technology of this model. Kidde produces both ionization and photoelectric combination units. The sensing type affects optimal placement — photoelectric is recommended for bedrooms and sleeping areas per NFPA guidance.

How does the CO alarm pattern differ from the smoke alarm pattern?

UL 2034 specifies a distinct alarm pattern for CO alarms: 4 beeps, pause, 4 beeps, pause — repeated. Smoke alarm patterns are typically 3 beeps or continuous. The distinct patterns allow occupants and emergency responders to identify which hazard is present. Check the 900-CUAR product manual for its specific alarm patterns.

Can I connect the 900-CUAR to my existing Kidde alarm network?

The 900-CUAR is compatible with Kidde's hardwired interconnect series. Verify that the connector type and interconnect voltage match your existing Kidde system before installation. Mixing incompatible brands in an interconnect network can prevent proper whole-system activation.

What happens to the alarm during a power outage?

The battery backup takes over seamlessly during AC power interruptions. The alarm continues monitoring and will activate if smoke or CO is detected during the outage. Check and replace the backup battery per the manufacturer's schedule.

When should the 900-CUAR be replaced?

Kidde recommends replacing smoke/CO combination alarms every 7–10 years. The 900-CUAR will emit an end-of-life signal when it is time for replacement. The manufacture date is printed on the back of the unit.

Is CO alarm coverage required by code?

CO alarm requirements vary by state and jurisdiction. Most states now require CO alarms in residential occupancies, particularly in bedrooms and adjacent to sleeping areas. Combination smoke/CO units like the 900-CUAR satisfy both requirements simultaneously where both are mandated.