In article .com, "Myrna" wrote:
In our home there are 3 smoke alarms, all wired into the house wiring.
All are the same age (about 22 yrs). There's a high pitched noise
coming from one of them.

In a recent discussion, one guy told me to replace all of them, not
just the one. He said new ones aren't compatible with the new ones. I
didn't ask him what he meant about being compatible.

So, can anyone tell me what this means? Do I have to replace all 3?

Smoke detectors do have a finite life -- the sensors degrade
over time and will eventually become non-functional. Typically,
fire departments and manufacturers recommend replacing the
smoke detectors every 10 years.

So, it's definitely time to replace all 3. You may even want
to add some more and ensure your property is up to current
code. You'll need to make sure you buy new detectors of the
right type.

I'd suggest you check the model number of the existing
detectors. It's almost certainly obsolete by now but the
manufacturer will likely be able to tell you what current
products are most compatible/equivalent.

This is what I did and the manufacturers web site guided
me to exactly the right products and plenty of other
useful information. With the right detectors and all of
that documentation, installation was a walk in the park.

In all it took an hour of research, an hour to run to the
store and an hour to install the things. Well worth the
effort to make my home and family a little safer.

--
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