Leak sensors, smart thermostats and the smart-home upgrades worth it

Some smart-home gadgets pay for themselves by preventing one bad day. Others are toys. Here's how to tell them apart, starting with the cheap sensors that catch water early.

The best smart-home devices aren't the flashiest. They're the ones that notice a problem while it's still small and tell you about it.

Water leak sensors

Battery-powered leak sensors sit on the floor and alert your phone when they get wet. Put them where water shows up first: under the kitchen sink, beside the water heater, behind the washing machine, next to the sump pump and under the dishwasher. They're inexpensive, and one early alert can save a great deal of damage.

Smart thermostats

A smart thermostat learns your schedule or follows your phone, so you're not heating an empty house. ENERGY STAR estimates that certified smart thermostats save about 8% on heating and cooling bills on average; your result depends on your habits, home and climate. Check compatibility first, including the common wire (C-wire) many models need, and whether you have a heat pump or more than one heating stage.

Connected smoke and CO alarms

Connected alarms send an alert to your phone when they sound, so you know about a problem when you're away, and many tell you which room. They still need testing and replacing like any other alarm.

Automatic water shut-off

A motorized valve on your main line, paired with leak sensors, closes the water automatically when a leak is detected. Installation usually needs a plumber. Some insurers offer a discount for them, so ask yours.

What to skip

Be wary of devices that need constant attention, lock you into one app with no way out, or solve problems you don't have. Start with water, heat and safety; add convenience later. Whatever you install, keep the model numbers and manuals together. Send Handyman a photo of the box or the label and it keeps the details with your home, along with the warranty. Start free.