Dave Platt wrote:
So what makes you think you need to replace a smoke detector every 5
years? I had units in my house that lasted over 20 years.

Have you actually tested it with (real or artificial) smoke, to make
sure that the sensor still senses?

The thing was constantly alarming.

Hitting it with a canned air duster blew out a cloud of dust.

The chirping went intermittant.

I then tossed the thing and went to Lowes.

$20 every 5 to 10 years is a trivial expense.

My understanding is that the sensor in the CO detectors, being
chemically based, does have a limited lifetime. As of 2009, ANSI/UL
specs require that such alarms begin chirping an "end of lifetime"
signal after 5 years of operation... and a couple of weeks after this,
you can no longer turn off the chirp.

Which reminds me that my portable CO monitor for the airplane is likely
at or near its end of life and they are quite a bit more than $20.


--
Jim Pennino