Adding Wi-Fi doesn’t always turn out to be as smart as it sounds. A smart smoke detector turns out to be dumber than I thought, even with Wi-Fi added.

Smart smoke detectors will let you know if a fire breaks out when you aren't home, but other than that they don't offer any extra benefits over a “dumb” model. And these devices introduce a problem: Most smart smoke detectors exclude one of two sensors to alert you about a fire. Every smart model I tested had only a photoelectric sensor, which picks up smoldering fires, while ionization sensors that pick up fast-burning fires were left behind. Ionization sensors are more likely to have nuisance alarms go off (while you're cooking, for example), but it's still a sensor you should have somewhere in your home, especially since modern building materials have shortened your window of time to escape a home fire .

It's not to say smart smoke detectors are useless, since what matters most is having a working smoke detector at all.…