Why interconnection matters
NFPA recommends interconnected smoke alarms so that when one sounds, all sound. The warning originating in a basement or distant hallway can then reach bedrooms sooner.
Compatibility matters
Not every alarm interconnects with every other alarm. Brand, model, wiring and system age affect compatibility. Replacing a single unit without checking the rest can create inconsistent behavior.
Testing the warning chain
A household test should confirm the intended audible response while everyone knows it is a test. If alarms do not respond as expected, record the models and call for service rather than experimenting with household wiring.
Safety references
Primary sources used for this page:
Manufacturer instructions and current local requirements control. For an emergency, call 911.