Kidde I12040 Hardwired Interconnect Smoke Alarm
- 120V hardwired, 9V battery backup included
- Ionization sensing, tuned to flaming fires per Kidde
- Up to 24 interconnected devices, 18 initiating
- One button for Hush and test
- Tamper resist locking, red LED alarm memory
- 10-year limited warranty, UL Listed
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A straightforward hardwired ionization alarm for interconnected home systems and contractor installs. It is tuned toward flaming fires, so pair it with photoelectric alarms for smoldering fire coverage.
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ASIN: B00PC5SKS2Model: i12040Category: Smoke Detectors & Fire Alarms
Overview
Hallways and bedrooms on a hardwired circuit get an ionization smoke alarm that runs on household power with a battery backup. A pre-stripped wiring harness connects to the house wiring, and interconnection lets one alarm trigger the rest of the system.
Builder friendly details stand out: a pre-stripped harness with tinned strands, a large mounting base that hides paint flaws, and a dust cover for construction sites. Ionization sensing may react later to smoldering fires, which is why Kidde itself recommends adding photoelectric alarms.
Who it's for
Suits new construction and replacement jobs where alarm wiring already runs to each ceiling location. Battery only households, and anyone wanting carbon monoxide sensing in one device, need a different model.
Pros and cons
- Battery pull tab activates without removing alarm
- Pre-stripped harness, no stripper tool needed
- Alarm memory shows which unit triggered
- Dust cover cuts construction nuisance alarms
- Ionization sensing may lag on smoldering fires
- No carbon monoxide sensing built in
- Requires a hardwired AC circuit
- Listing specs conflict on sensor type
Performance notes
Detection speed depends on the ionization chamber, which responds to the invisible particles of flaming fires sooner than to the visible smoke of smoldering ones. In an interconnected system the initiating alarm flashes its red LED, so tracing the source after a trip is quick. The battery backup carries the alarm through power outages, and run down protection limits low battery chirps when AC power is absent.
Specifications
| Brand | Kidde |
|---|---|
| Model | i12040 |
Frequently asked questions
Is the Kidde i12040 a photoelectric smoke alarm?
No. Its bullets and description describe ionization sensing technology. Kidde recommends installing both ionization and photoelectric alarms to cover flaming and smoldering fires.
Does the Kidde i12040 detect carbon monoxide?
No. It is a smoke alarm only, though it can be interconnected with Kidde CO and heat alarms.
Do I need to remove the Kidde i12040 from its bracket to activate the battery?
No. A front battery pull tab activates the included 9V backup battery with the alarm still on its mounting bracket.
How does the hush feature work on the Kidde i12040?
One button operates both Hush and alarm test. Pressing it silences nuisance alarms from non-emergency situations such as overcooked dinners.