wrote:
On Thu, 10 Feb 2005 05:25:23 GMT, "Bill Browning"
wrote:


They say to replace your CO alarms every 5 or 10 years. Why? If they still
test OK, why replace them?
Bill B.



imho:

I was told in my nfpa based training every 10, since a decade passing
brings new 'features' in the new products, and circuitry isn't tested
to last beyond a decade of use.

Might be a UL issue.

hth,

tom @ www.URLBee.com

That sounds almost like an old safety NCO that said a knot
in an electrical cord was bad because the electrons had to
speed around the corners and that made the wire hot.

Apparently your instructors fall into the same category. I
would be very leery of any of their personal descriptions of
how things work.

Some sensors have a limited lifetime. But many old smoke
detectors are based on a light sensor and there is no reason
that the circuit wouldn't last for decades. My original
smoke detector still works after nearly 30 years. I've got
another 10 year old smoke detector (ionization type) which
is still so sensitive it goes off every time somebody make
toast.