Sensors and alarms
Updated
Water leak sensors and shutoff valves, smart smoke and carbon monoxide alarms, door and motion sensors: placement and what each alert is worth.
Sensors are cheap, quiet and often the most useful part of a smart home: a leak sensor that catches a slow drip, a smoke alarm that reaches your phone when you are out, a door sensor that tells you the garage was left open.
Life-safety alarms follow their own rules: install smoke and CO alarms where fire safety agencies recommend and replace them on schedule. A smart add-on never replaces a working, listed alarm.
See the water leak protection kit.
Kits 7
KitWater leak protection kit for a houseFive leak sensors, an automatic shutoff valve and a hub: the shopping list to catch leaks early and stop them before they flood the floor, with…KitNo-subscription home security kitA local hub, door and motion sensors, a siren and cameras that record to a card or drive: a home security setup with no monthly fee, with…KitVacation home monitoring kitLeak and freeze sensors, a power-loss alert, cameras, a router on a UPS and cellular backup: the kit that lets you watch an empty home or second…KitSmart smoke and CO alarm kit for a 3-bedroom homeSix interconnected alarms, three of them smoke and CO combinations, plus a fire extinguisher and an escape plan: a shopping list that covers every…KitVisual and vibrating alert kit for deaf and hard of hearingSmoke alarms with strobes and bed shakers, a doorbell that flashes your lights and a few smart bulbs: a shopping list for alerts you can see and…KitLaundry room smart kitLeak sensors, cycle-done alerts and a humidity sensor for the laundry room, plus the dryer vent and hose upgrades that cut the usual fire and…KitToddler-proofing alerts kit for crawlers and walkersDoor and window sensors, a loud chime and a hub tell you when a toddler opens an exit. A shopping list with prices, placement and the safety notes…
Guides 11
GuideDoor and window sensors: 10 automations that are worth setting upA $10–$25 contact sensor does far more than guard the front door. Ten practical automations, from open-window alerts to a fridge door left ajar,…GuideWhere to place motion sensors: height, angle and heat sources to avoidMount a PIR motion sensor at about 6–8 feet in a corner, aimed across the walking path and away from vents and sunlight. Room-by-room advice for…GuideMotion sensors and pets: how to avoid false alarmsPet-immune motion sensors, higher mounting and perimeter-first alarms can keep a cat or dog from setting off your system. What works, what does…GuideSmart home insurance discounts: which devices count and what to askSome insurers credit leak sensors, shutoff valves, smoke alarms and monitored alarms; others do not. Learn which devices tend to count, what proof…GuideWireless interconnected smoke alarms: what to know before buyingWhen one alarm senses smoke, every alarm in the house sounds. Here is where to put them, why brands usually cannot be mixed and when a hardwired…GuideWhere to place carbon monoxide detectorsPut a CO alarm on every level and outside every sleeping area. Here are the spots to avoid, what to do about an attached garage and generator, and…GuideSmoke alarm near the kitchen: stopping false alarmsKeep the alarm about 10 feet from the stove, use the hush button and ventilate. Never pull the battery, and do not replace a bedroom alarm with a…GuideSmart water shutoff valve: actuator or inline valveA clamp-on actuator fits a quarter-turn main valve and costs much less; an inline motorized valve is installed by a plumber. Check your valve,…GuideSump pump alarm and backup optionsA high-water alarm warns you before the basement floods, a power alert tells you the pump has no electricity, and a battery backup keeps pumping.…GuideHeat alarm or smoke alarm for the garage: which one fitsSmoke alarms are not designed for garages, where exhaust, dust and temperature swings trigger false alarms. A heat alarm is the usual choice. Here…GuideWhich door, motion and leak sensors for Home Assistant or SmartThings?Pick the radio first: Zigbee, Z-Wave or Matter over Thread. Then match battery type, reporting and your hub. This guide helps you choose sensors…
Comparisons 6
ComparisonDIY vs professionally monitored home security: costs and trade-offsA self-monitored system costs little per month and puts you in charge; professional monitoring adds a call center, a contract and sometimes an…ComparisonmmWave presence sensor vs PIR motion sensor: which one fitsPIR sensors see movement and run for years on a coin cell; mmWave radar also sees a person sitting still, but costs more and needs power. Here is…ComparisonSmart smoke alarm vs smoke alarm listenerA smart alarm replaces your old alarm. A listener adds a phone alert to alarms you already own. Compare cost, interconnect, CO coverage, wiring…ComparisonHardwired vs sealed 10-year battery smoke alarms: what fits your homeHardwired alarms tie into house wiring with a battery backup; sealed-battery alarms run for up to ten years on their own. Costs, installation and…ComparisonPhotoelectric vs ionization smoke alarms: how they differ and what to buyThe two sensor types respond to different fires. Here is how they differ, why dual-sensor alarms exist, and which type suits a kitchen, a bedroom…ComparisonWater leak sensors or a whole-home flow monitorLeak sensors catch water on the floor where a leak starts. A flow monitor watches the main line for water running when it should not. See what…