Butch Haynes wrote:
"Myrna" wrote in message
oups.com...
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?

Thanks,
Myrna


Fire departments recommend using battery operated ones that are independent
of house current and could be compromised in a fire.

In many cases 120VAC detectors are required in new construction, and
therefore likely it would be a code violation to replace them with
battery operated units. However, there are detectors available which
are 120VAC and also use a 9V battery for backup power should the 120VAC
power fail.

nate