On Sat, 17 Jan 2015 14:01:23 -0800 (PST), wrote:

I have a condo and it has the original smoke detectors, FireX. Probably about 20 years old. they don't take batteries, that's probably why they have not received much attention. The are hardwired to AC with a signal wire to the other 2 detectors. Don't believe they are on a separate circuit, should they be ?

Should they be replaced ?

Recommendations !?

Thanks

Look for an expiration date on back of the detector. Ten years is max?
Replace them. BTDT -- from the date it is stamped or labeled.