Smart Home Wiring Basics: What to Know Before You Buy Devices

Smart switches and the neutral wire

A smart switch needs a trickle of power to stay connected even when the light is off. Most get it from a neutral wire in the switch box. Homes built before the mid 1980s often have switch boxes with no neutral. You can choose a no-neutral model, which is fussier about bulb types, or have a neutral added.

Three-way switches

Lights controlled from two locations need a smart switch designed for it, usually one main switch plus a companion. Mixing a smart switch with an ordinary three-way rarely works.

Dimmers and LEDs

Use dimmable LED bulbs and a dimmer rated for them. Flicker, buzz and lights that glow when off are compatibility problems. See lighting installation for layout help.

Smart thermostats and the C-wire

Many smart thermostats need a common wire for steady power. Older systems may have only two or four wires at the thermostat. An electrician or heating contractor can run a new cable or use a spare conductor. A thermostat that runs low on power in January is one you do not want.

Video doorbells

Wired video doorbells draw more than an old chime transformer was built to supply. Low-power warnings and a doorbell that drops offline in cold weather are the symptoms. A transformer upgrade is a quick fix. See doorbell wiring.

Do not skip the network

Every smart device relies on your network. Ethernet to a few well-placed access points does more for reliability than any single gadget. If walls are open for a remodel or a new build, pull cable then. See new construction wiring.

Useful for northern winters

• Temperature and freeze sensors that alert your phone
• Leak sensors by the water heater and sump pit
• Smart outlets to schedule engine block heaters
• Outdoor lighting on a sunset schedule. See outdoor lighting

Want it planned and installed as one system? Visit smart home wiring.