[HH] Smoke detectors self-destruct

[Greg Rundlett (freephile)]

I bought a house 6 years ago, and I was perplexed this week as ALL the
First Alert combo smoke + CO detectors started chirping and went bad.  At
first I thought it was just a battery problem. Then I thought it was a
malfunctioning unit that was interconnected with the rest, so I would need
to trace it to the 'bad' dectector.

Unfortunately, it's more "sinister" than that.  The First Alert smoke
detectors have and "End of Life" feature that: [1]

"is a simple counter that begins working once the unit is activated either
by plugging it in, hardwiring or inserting the battery. Then after
approximately 120 months of operation (or other timing as coded in the
alarm which may be 60 or 72 months)"

cause the unit to essentially self-destruct.  It will alert constantly, and
will need to be replaced.

Since my detectors were warranted for 5 years, the self-destruct timer was
set for 6 years.

Just spreading the word because you should AVOID any detector that is UL
2034 [2] certified (if possible?)

Does anyone know of a brand that doesn't?

Does anyone have knowledge of hacking on smoke detectors?  Not that I have
time or skill to actually hack on IC if it were possible, I'm just curious.

[1]
http://www.brkelectronics.com/faqs/diy/how_long_do_co_and_co-smoke_combo_alarms_last
[2] https://standardscatalog.ul.com/standards/en/standard_2034

~ Greg

Greg Rundlett
https://eQuality-Tech.com
https://freephile.org
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