# AlarmSwap

> What replaces the smoke alarm on your ceiling. Model-by-model answers for hardwired smoke and CO alarms: how old it is, when it expires, what replaces it, and which adapter fits. Every fact links to the maker or to NFPA, USFA or CPSC.

Facts are restated in our own words from alarm makers, NFPA, USFA and CPSC. Nothing here is copied from those pages. The site has no star ratings and no review counts. Affiliate links are off (`affiliates_enabled` is false). Search engines and AI crawlers may use these pages; see https://smokealarmswap.com/robots.txt.

## Guides

- [How to find your smoke alarm's date and when it expires, by brand](https://smokealarmswap.com/guides/smoke-alarm-date-and-expiry/): Where each brand prints the manufacture date on a smoke or CO alarm, how many years each maker gives it, and what to do when the date is missing. Kidde, First Alert, Google Nest Protect, X-Sense, USI and Firex, with links to each maker. Last checked 2026-10-31.


## Models

- [Firex i4618](https://smokealarmswap.com/models/firex-i4618/): Firex i4618 and i4618AC hardwired ionization smoke alarms are discontinued. Kidde's named upgrade (20SAR), the 20-9003 adapter for the old Firex plug, interconnect notes and the ten-year rule. Last checked 2026-10-31.

- [Kidde i12040](https://smokealarmswap.com/models/kidde-i12040/): Kidde i12040 hardwired ionization smoke alarm with Hush: date code location, ten-year replacement, approved 9 V backup batteries, interconnect limits and the 20-9003 plug adapter. Last checked 2026-10-31.

- [Kidde i12060](https://smokealarmswap.com/models/kidde-i12060/): Kidde i12060 hardwired ionization smoke alarm: where the date code is, when it is due for replacement, its backup battery, interconnect limits and the Kidde adapter that fits its old wiring plug. Last checked 2026-10-31.


## Brands

- [Kidde](https://smokealarmswap.com/brands/kidde/): Kidde model pages on AlarmSwap: where the date is, when the alarm is due, and which adapter those pages cite.

- [Firex](https://smokealarmswap.com/brands/firex/): Firex model pages on AlarmSwap, including the replacement and adapter facts cited from Kidde for these alarms.

- [First Alert / BRK](https://smokealarmswap.com/brands/first-alert/): Where the date-and-expiry guide says First Alert prints the manufacture date, and when it says to replace the alarm. No First Alert model page yet.


## Also
- [How we source](https://smokealarmswap.com/about/): which hosts count as a source, and how a fact is checked.
- [Disclosure](https://smokealarmswap.com/disclosure/): affiliate links are off, and how a where-to-buy list would be marked if that changes.
- [Full text for models and guides](https://smokealarmswap.com/llms-full.txt): the same pages with each fact and its source URL.