First Alert BRK Hardwired Smoke Detector with Battery Backup Ionization – Model 1046835

The First Alert BRK 1046835 is the contractor-standard hardwired ionization smoke alarm that residential builders and electrical contractors specify on most new construction projects across the United States. As a BRK hardwired smoke detector, this unit comes from BRK Brands, the parent company that also makes First Alert, and represents the value-tier builder-focused product within the broader First Alert and BRK alarm lineup. As a BRK ionization smoke alarm, the First Alert BRK 1046835 uses ionization sensing technology for fast detection of flame-front fires from paper, kitchen grease, and rapidly spreading flames. As a hardwired smoke detector 9V backup, the unit connects directly to the home’s 120V electrical system as primary power and includes a replaceable 9V battery for backup operation during utility outages, which is the traditional builder-grade configuration that allows for easy field battery replacement without changing the entire detector. As a BRK interconnect smoke alarm, the First Alert BRK 1046835 uses mesh interconnect technology to coordinate alarm sounds across up to 12 smoke alarms plus 6 additional CO or heat alarms on a single system, providing whole-home protection where any single alarm detection triggers every alarm to sound. Every First Alert BRK 1046835 ships nationwide from IB Lighting with free shipping. Manufacturer specifications are available at the official BRK Electronics website.

First Alert BRK 1046835 Key Highlights

BRK vs First Alert: Same Parent Company, Different Product Lines

The First Alert BRK 1046835 carries both the First Alert and BRK brand names because both brands are made by the same parent company, BRK Brands. The distinction between them matters for buyers comparing products in the BRK Brands lineup.

BRK is the historical contractor-focused brand that has been making residential smoke alarms for the construction industry since the 1960s. BRK products are typically the builder-grade specifications that residential contractors, multi-family developers, and electrical contractors install in volume on new construction projects. The First Alert BRK 1046835 follows this contractor-grade positioning with a 9V replaceable battery backup (traditional builder spec), mesh interconnect for up to 12 smoke alarms (handling large residential and multi-family installations), and a price point that scales for whole-home and whole-building specifications.

First Alert is the consumer-focused brand within the same parent company. First Alert products typically target the homeowner and retail channel with consumer features like sealed 10-year lithium batteries (no maintenance), single-pack and 2-pack retail packaging, and premium positioning. The First Alert First Alert 1046848 hardwired smoke detector represents this consumer side with a sealed 10-year battery instead of the replaceable 9V used in the BRK 1046835.

Both First Alert and BRK alarms interconnect with each other on the same mesh system, which means mixed-installations are possible. Builders often spec the First Alert BRK 1046835 throughout most of the home for cost efficiency and add a premium First Alert sealed-battery unit in the master bedroom or critical sleeping areas. All units coordinate through the same interconnect signal regardless of which brand label is on the housing.

Hardwired Installation: 120V Primary Power Plus 9V Battery Backup

The First Alert BRK 1046835 is a hardwired smoke detector, which means it connects directly to your home’s 120V electrical system as its primary power source. Under normal grid-powered operation, the alarm draws continuous power from the household electrical circuit, eliminating the dead-battery failure mode that affects pure battery-only alarms. The 9V battery serves only as backup power for the periods when utility power is lost.

The hardwired configuration is required by the International Residential Code (IRC) for new construction throughout most of the United States. Building inspectors expect to see hardwired interconnected smoke alarms in any new home construction, major renovation, or addition that triggers code compliance. The First Alert BRK 1046835 satisfies these code requirements at a price point that suits whole-home installation across multiple alarm locations.

The 9V battery backup ensures the First Alert BRK 1046835 continues to monitor for smoke during power outages. When utility power fails, the battery takes over instantly and the alarm continues to operate normally throughout the outage. The 9V battery should be replaced annually or when the alarm produces a low-battery chirp signal, whichever comes first. The battery compartment is accessible from the front of the alarm without dismounting the unit, which speeds annual maintenance compared to designs requiring full removal.

For new construction or major renovations where the wiring is being run anyway, the First Alert BRK 1046835 is installed on a dedicated 15-amp branch circuit (typically AFCI-protected per current NEC) running from the electrical panel to each alarm location. The Southwire 14/3 NM-B 250 ft Romex SIMpull is the standard cable specification for residential smoke alarm wiring, providing the four conductors (hot, neutral, interconnect signal, ground) needed in the system.

9V Battery Backup vs Sealed Lithium: Why Each Is Right for Different Buyers

The First Alert BRK 1046835 uses a replaceable 9V battery for backup power. This is meaningfully different from sealed 10-year lithium battery designs found in some premium hardwired alarms, and the choice between them is a real decision point for buyers comparing options.

9V replaceable battery (this product) advantages: Lower upfront cost. Field-replaceable battery means the alarm itself can have a longer effective service life beyond the battery cycle (alarm typically lasts 10 years, but is not tied to battery service life). Battery replacement is a quick maintenance task that homeowners or building maintenance staff can perform without specialized tools or replacement units. Multi-family property managers can stock 9V batteries in bulk and rotate them through dozens of units on a predictable annual schedule.

9V replaceable battery considerations: Requires annual battery replacement (or when the low-battery chirp triggers, whichever comes first). Homeowners who skip the replacement task can end up with a backup battery that fails to engage during a power outage. The “set it and forget it” advantage of sealed 10-year designs is not available here.

Sealed 10-year lithium (e.g., First Alert 1046848) advantages: No battery replacement needed for a full decade. Tamper-resistant (the battery cannot be removed or replaced by tenants or family members). Sealed against humidity and dust. Lower long-term maintenance burden.

Sealed 10-year lithium considerations: Higher upfront cost. When the battery reaches end-of-life, the entire alarm unit is replaced (not just the battery). Some jurisdictions specifically require sealed 10-year batteries by law, while other jurisdictions accept either type.

For most new construction projects where the builder is installing alarms at scale, the First Alert BRK 1046835 with 9V replaceable battery is the more cost-effective specification. For homeowners who specifically value not having to replace 9V batteries annually, or for jurisdictions requiring sealed 10-year batteries, the First Alert 1046848 is the right specification. Both interconnect on the same wiring system, so mixed installations are possible.

Mesh Interconnect: Up To 12 Smoke Alarms Plus 6 CO/Heat Alarms

The First Alert BRK 1046835 supports the BRK Brands mesh interconnect system, which allows up to 12 smoke alarms plus up to 6 additional CO alarms or heat alarms (18 total devices) to operate as a single coordinated system. When any single alarm in the network detects smoke (or CO, or heat for the additional alarm types), the alarm signal propagates through the interconnect wiring and every alarm in the network sounds simultaneously, providing whole-home alert regardless of which room or floor the fire originated in.

This is a meaningful capacity advantage over some legacy interconnect systems that supported only 6 to 8 alarms in a single network. The 12-smoke-alarm capacity handles all but the largest single-family residential installations, and the addition of 6 CO/heat alarm slots allows a complete home life-safety system on a single coordinated mesh. The First Alert BRK 1046835 is specifically designed to be the smoke alarm building block of this complete system.

The mesh interconnect signal travels on a single conductor between alarms (the “red” wire in standard 14/3 NM-B installations). Each alarm in the system can both transmit an alarm signal (when it detects smoke) and receive an alarm signal (causing it to sound when any other alarm transmits). Latching alarm indicators on each unit identify which specific alarm initiated the system alarm, which speeds emergency response and post-event diagnosis. After an alarm event ends, the initiating unit displays a flashing green LED for two seconds on and two seconds off, identifying itself as the source until manually reset.

Smart Features: Latching Indicator, 8-Hour Silence, Perfect Mount

The First Alert BRK 1046835 includes several practical features that go beyond basic smoke detection and meaningfully improve the day-to-day usability of the alarm.

Latching alarm indicator: When the alarm triggers, the LED on the alarm face rapidly flashes red. After the alarm condition subsides, the initiating unit stores the alarm event in memory (“latches” the information) and displays a flashing green LED at two seconds on, two seconds off until manually reset. This identification feature is genuinely useful when an alarm event has occurred and the homeowner or maintenance staff needs to identify which specific alarm started the chain. Without latching indicators, identifying the originating alarm in a multi-alarm system after the smoke clears can be impossible.

Test/silence button with 8-hour silence: The single button on the alarm face handles both functions. A short press tests the alarm (causing all interconnected alarms to sound briefly, confirming system operation). A long press during an active alarm silences the unit for up to 8 hours, which is the right duration to handle cooking nuisance alarms without leaving the system disabled overnight. The silence function does not disable the alarm permanently and the unit will automatically re-enable if smoke continues to be detected.

Perfect Mount bracket: The included mounting bracket attaches to the ceiling-mounted electrical junction box and provides a wide rotation range for ideal alignment of the alarm. Keyhole slots in the bracket allow installation without fully removing the box screws, which speeds new construction installations where dozens of alarms are being mounted in a single day. The alarm twists onto the bracket and locks in place with a tamper-resistant feature that prevents accidental dismount.

Dust cover for construction: A removable dust cover protects the sensing chamber from construction debris during framing, drywall, and finish work. Construction dust accumulating inside the sensor reduces sensitivity and triggers nuisance alarms, so the cover stays in place until the unit is officially commissioned at final inspection. The cover is removed and discarded at commissioning, after which the alarm is ready for normal operation.

Ionization Sensing Technology

The First Alert BRK 1046835 uses ionization sensing technology to detect smoke. Ionization sensors are especially sensitive to fast-flaming fires from paper, kitchen grease, and rapidly spreading flames. These fast-flame fires produce small smoke particles that ionization sensors detect quickly, providing rapid alarm response in the kitchen, living, and dining areas where these fire types are most likely to occur.

Ionization sensors complement photoelectric sensors, which are more sensitive to the larger smoke particles produced by slow smoldering fires (mattresses, upholstered furniture, smoldering electrical wiring). The National Fire Protection Association recommends both sensor types for complete residential coverage. Most professional installers spec ionization alarms like the First Alert BRK 1046835 in living spaces and kitchen-adjacent areas while spec’ing photoelectric alarms in bedrooms and sleeping areas. The two sensor types interconnect on the same wiring system and trigger each other when any alarm detects smoke.

For photoelectric sensing in battery-only sealed configurations, the First Alert photoelectric smoke detector 2-pack is the right specification. For mixed hardwired installations using both sensor types, First Alert and BRK offer hardwired photoelectric alarms that interconnect with the First Alert BRK 1046835 on the same circuit.

When Hardwired Alarms Are Code-Required

The First Alert BRK 1046835 is specifically the right product when hardwired interconnected smoke alarms are required by code, which covers most new construction projects in the United States.

New construction: The International Residential Code (IRC) requires hardwired interconnected smoke alarms with battery backup in all new single-family and two-family residential construction, virtually universally across US jurisdictions. The First Alert BRK 1046835 satisfies this requirement at the contractor-grade price point that residential builders need for whole-home installations covering 5 to 8 alarm locations per home.

Major remodels and additions: Most jurisdictions require existing battery-only alarms to be upgraded to hardwired interconnected when major renovation work is performed. The First Alert BRK 1046835 is the cost-effective specification for these upgrade scopes.

Multi-family residential: Apartments, condominiums, dormitories, and similar multi-unit residential construction typically require hardwired interconnected alarms in each unit. The contractor-grade pricing of the First Alert BRK 1046835 makes it the default specification for large multi-family projects where hundreds of alarms may be needed across a single development.

Replacement of existing BRK or First Alert hardwired alarms: The First Alert BRK 1046835 is a direct replacement for existing BRK Brands hardwired alarms reaching end-of-service-life. The interconnect signaling is compatible with prior generation BRK and First Alert hardwired alarms, allowing piecemeal replacement of units as needed without rewiring.

Wiring Requirements for the First Alert BRK 1046835

Installing the First Alert BRK 1046835 requires a properly designed electrical circuit meeting NEC and IRC requirements. For new construction or major renovations, the wiring is run during framing rough-in by the electrical contractor as part of the overall electrical scope. For retrofit installations through finished walls and ceilings, the work is meaningfully more complex but uses the same wiring topology.

The smoke alarm circuit consists of a dedicated 15-amp branch circuit from the panel, typically protected by an arc-fault circuit interrupter (AFCI) breaker as required by current NEC. The circuit feeds the first alarm in the home, then continues to each additional alarm in series. The cable is 14/3 NM-B Romex with ground: black for the hot, red for the interconnect signal, white for the neutral, and bare copper for the ground. Each First Alert BRK 1046835 has a Quick-Connect 3-wire pigtail (black hot, white neutral, red interconnect) that attaches to the household wiring using the included wire connectors.

The 14/3 cable carries the interconnect signal between alarms on the red wire, which is how the mesh interconnect works. When any First Alert BRK 1046835 detects smoke, it transmits the alarm signal on the red wire, and every other alarm on the same circuit receives that signal and sounds its own alarm. The Southwire 14/3 NM-B 250 ft Romex SIMpull is the standard cable specification for residential hardwired smoke alarm circuits, and a single 250-foot spool handles a complete 5 to 7 alarm system for a typical single-family home.

Important: This Is a Smoke Detector, Not a CO Detector

The First Alert BRK 1046835 is specifically a smoke alarm, not a carbon monoxide (CO) alarm. The ionization sensor detects smoke particles only. Carbon monoxide is an invisible, odorless gas produced by incomplete combustion (gas appliances, fireplaces, automobile exhaust, gas-powered generators) that has its own dangerous health effects entirely separate from fire smoke. CO detection requires a different sensor type and a separate alarm.

Every US home should have BOTH smoke detection and CO detection. The First Alert BRK 1046835 mesh interconnect system supports adding CO alarms to the same interconnected network, with up to 6 CO or heat alarm slots available alongside the 12 smoke alarm slots. This allows builders and homeowners to deploy a complete fire-and-CO life-safety system on a single coordinated mesh.

If your home uses any gas appliances (gas furnace, gas water heater, gas range, gas fireplace, gas dryer), uses a wood-burning fireplace or wood stove, has an attached garage, or operates a gas-powered standby generator like a Generac Guardian standby generator, you have CO risk and need dedicated CO detection in addition to the smoke detectors. Add compatible BRK or First Alert CO alarms to the mesh interconnect network for complete coverage.

First Alert BRK 1046835 Specifications

First Alert BRK 1046835 FAQs

Who the First Alert BRK 1046835 Is Built For

The First Alert BRK 1046835 serves three clear buyer types. The first is residential builders and general contractors specifying smoke alarms for new construction at the contractor-grade price point. For these buyers, the First Alert BRK 1046835 is the value-tier hardwired alarm that satisfies code requirements at a cost-effective specification. A typical single-family home build needs 5 to 7 of these units plus the matching 14/3 NM-B Romex for the interconnect circuit, and the BRK-branded contractor pricing scales for whole-home installations.

The second buyer is the multi-family developer or property manager handling apartment buildings, condominium projects, dormitories, or similar large-scale residential. For these buyers, the contractor-grade pricing of the First Alert BRK 1046835 makes it the default specification when hundreds of alarms are needed across a single development. The 9V replaceable battery configuration also supports the predictable annual maintenance schedules that multi-family property management requires.

The third buyer is the electrical contractor doing major remodels and additions where smoke alarm system upgrades are triggered by the scope of work. When existing battery-only alarms must be upgraded to hardwired interconnected alarms during a major remodel, the First Alert BRK 1046835 is the cost-effective specification for the upgrade. Browse the broader IB Lighting electrical wire and safety product collection for related products needed to complete the smoke alarm circuit installation.

First Alert BRK 1046835 vs First Alert 1046848: Which Should You Buy?

The First Alert BRK 1046835 and the First Alert 1046848 are siblings in the BRK Brands hardwired ionization lineup. Both are hardwired, both are ionization-sensing, both interconnect on the same mesh signal, and both satisfy IRC code requirements for new construction. The choice between them is driven by battery configuration, brand positioning, and budget.

Choose First Alert BRK 1046835 (this product) for new construction at the contractor-grade price point. The 9V replaceable battery configuration is the traditional builder spec and supports the predictable annual maintenance schedules that residential builders, multi-family developers, and property management companies use. At $24 per unit versus the First Alert 1046848 at $31, the BRK 1046835 is meaningfully more affordable when ordering 5 to 7 units for a whole-home installation (saving $35 to $50 per home) or hundreds of units for multi-family projects (saving $2,000 to $10,000+ per project).

Choose First Alert 1046848 if you want the sealed 10-year lithium battery configuration that eliminates the annual 9V battery replacement task entirely. This is the right pick for homeowners who want set-it-and-forget-it maintenance, for jurisdictions specifically requiring sealed 10-year batteries, and for installations where the additional cost is justified by the lower long-term maintenance burden. The premium consumer positioning of the First Alert brand also matters in some retail and homeowner contexts.

Both products interconnect on the same wiring system, so mixed installations are possible. Many builders spec the BRK 1046835 throughout the home for cost efficiency while adding the First Alert 1046848 in the master bedroom or other critical locations.

Installation Tips for the First Alert BRK 1046835

Installing the First Alert BRK 1046835 requires electrical work and typically a permit and licensed electrician. For new construction during framing rough-in, the install is straightforward for the electrician handling the overall electrical scope. For retrofit installs through finished walls and ceilings, the work involves running 14/3 NM-B Romex through wall cavities and ceiling joists, which is meaningfully more labor-intensive.

For each alarm location, the standard installation involves mounting an electrical junction box to a ceiling joist (or wall stud) where the alarm will be installed, running 14/3 NM-B Romex from the panel to the first alarm box and from each alarm box to the next alarm in the interconnect chain, and protecting the entire smoke alarm circuit with an AFCI breaker at the panel. The first alarm in the chain connects to all four conductors (hot, neutral, ground, plus interconnect signal). Subsequent alarms connect to the same four conductors through pass-through wiring.

The First Alert BRK 1046835 attaches to the junction box using the included Perfect Mount bracket. The keyhole slots in the bracket allow installation without fully removing the box screws, which speeds new construction installations. The Quick-Connect 3-wire pigtail on the alarm connects to the household wiring using the included connectors. Install the 9V backup battery in the battery compartment before twisting the alarm onto the bracket. Once power is applied, the alarm performs an initial self-test (audible chirp confirming operation) and enters normal monitoring mode. Test each alarm by pressing the test button; if interconnected correctly, every alarm in the system should sound simultaneously when any single test button is pressed.

Leave the included dust cover in place throughout construction to protect the sensor from dust accumulation. Remove and discard the cover at final commissioning before final inspection.

Maintenance and 9V Battery Replacement

The First Alert BRK 1046835 requires routine maintenance to deliver reliable life-safety performance over its 10-year service life. The 9V replaceable battery means battery maintenance is part of the regular schedule, unlike sealed 10-year alarms where the battery is not replaced.

Monthly test: Press the test button on any one alarm in the interconnected system. If interconnection is working correctly, every alarm in the system should sound simultaneously. This confirms both the individual alarm operation and the interconnect signal integrity. If only one alarm sounds during a test, the interconnect wiring needs troubleshooting. Monthly testing is the most important maintenance task for the system.

Annual 9V battery replacement: Replace the 9V battery in each First Alert BRK 1046835 unit annually, or whenever the alarm produces a low-battery chirp signal, whichever comes first. The battery compartment is accessible from the front of the alarm without dismounting the unit. Use a quality alkaline 9V battery for best performance. Mark the install date on the new battery with a permanent marker to track the next replacement cycle.

Periodic cleaning: Vacuum the exterior of each alarm every 6 months to remove dust accumulation from the sensing chamber vents. Dust accumulation degrades sensor sensitivity over time. A soft brush attachment on a household vacuum cleans the vents adequately without damaging the unit.

10-year unit replacement: At the 10-year service life mark, replace the entire First Alert BRK 1046835 unit. The ionization sensor and electronics reach end-of-service-life regardless of how many batteries have been replaced along the way. When replacing one alarm in an interconnected system, consider replacing all alarms in the system at the same time so they age together and reach end-of-life together, simplifying future replacement scheduling.

Browse the complete IB Lighting electrical and safety product collection, compare with the First Alert 1046848 (sealed 10-year battery sibling) or the battery-only First Alert photoelectric smoke detector 2-pack, pair with the Southwire 14/3 NM-B 250 ft Romex SIMpull needed for hardwired interconnect wiring, consider pairing with a Generac standby generator for outage protection, or visit our customer FAQ hub. Manufacturer technical sheets are available at the official BRK Electronics website.