Replace outdated hardwired smoke detector - brittag/maintenance GitHub Wiki
| Aspect | Info |
|---|---|
| Context | Residence |
| Date started | 2024-12 |
| Date finished | 2024-12 |
| Status | Complete |
| Summary of outcome | Improved. Still needs work. |
Background
When you move into a home, convert a room into a sleeping room (such as adding a guest bed), or visit family members who may not have checked their home recently:
- Check whether there are smoke alarms in necessary places (some guidelines; state law should give specific requirements)
- Take each smoke alarm off the ceiling or wall:
- Check date of manufacture. Older than 10 years? Replace. Newer than 10 years? Fill out the little date label on the side of the smoke detector to make it easier to check next time, and add a calendar reminder in your phone for the replacement date.
- Check whether it's a battery-powered smoke alarm installed over a wiring harness for a hardwired smoke alarm. Hardwired is better and may be required by your state.
- Put them back, put in ear plugs, and test each smoke alarm.
Problem
Home built in the early 1900s had a bedroom with a hardwired Firex 120-538B smoke detector from the 1990s. Ceilings in other rooms showed signs of harnesses for hardwired smoke detectors that had been covered, painted over, and replaced with battery-powered smoke detectors. Not great!
The best approach would have been to uncover and upgrade all of the harnesses so that we could install a full set of new hardwired, interconnected smoke detectors. Rewiring the connectors to support new smoke detectors shouldn't be too hard. However, many tasks in this particular house turn out to be surprisingly complicated because of bad DIY efforts by past owners.
In this case, relevant state law only seemed to require hardwired, interconnected smoke detectors in homes built or renovated after 1980. Checked the city's permit records online and couldn't find any qualifying remodels since 1980. So fixing this properly seemed to be a recommendation rather than a requirement.
Scope for the time being was limited to replacing the outdated Firex smoke detector.
Approach
Retrofit options that did not look promising:
- Looked into whether we could use this Kidde hardwired smoke detector kit that includes an adapter for Firex smoke detectors. That's a Kidde KA-F2 adapter labeled as compatible with Firex models FADC, ADC, and AD. Since this room had a Firex 120-538B, the kit doesn't look compatible.
- First Alert sells a BRK ADF-12 adapter labeled as compatible with "406 (G-6), 4518 (ADC), 4618 (FADC), 484 (PG-40), 4480 (PAD), 5700 (ADH), and 499 Firex alarms", but that doesn't look compatible either.
Retrofit options that might work:
- A company sells a replacement hardwired smoke detector kit labeled as compatible with Firex 120-538B connectors ($27). Looks suitable, but this was an unknown seller that could take an unknown amount of time to deliver the product.
- That kit includes an adapter you can buy on its own: Kidde KA-F adapter ($26 for 6, $4.30 each). It has reviews that say it's compatible with Firex 120-538B connectors if you "clip the center plastic piece off to make the adapter fit snugly".
- Rewire it with a new connector
For the time being, we decided to replace the Firex detector with one of the new battery-powered smoke detectors that we already had. After removing the old mounting plate, a First Alert model with a replaceable battery was too small to cover the hole properly, but a different model with a ten-year battery was wider and fit over the hole nicely. Tested it after installation to make sure it worked.
Outcome
The relevant bedroom has a new, working battery-powered smoke detector.
Next steps
Home should still get upgraded to a new set of hardwired, interconnected smoke detectors, ideally dual-sensor (both ionization and photoelectric).