On Saturday, March 25, 2017 at 4:28:50 PM UTC-4, wrote:
The smoke detectors are most likely connected to a breaker that won't normally be turned off by a homeowner. Typically it is wired to the furnace circuit. Open up the panel, it should be the only breaker with 2 hot wires connected to the breaker.


Maybe, assuming the breaker is rated for double tapping. I've seen quite
a few homes here in NJ with hardwired smoke detectors both old and new
construction, none had double tapped breakers on anything.