A Smart Tip for Smart Thermostats
What to know before installing a smart thermostat
TOH plumbing and heating expert Richard Trethewey shows a homeowner how to swap in a smart thermostat, an easy DIY job if the right wiring is in place.
The latest thermostats can take orders from a smartphone, tally your energy use, and even track your location, turning the heat down when you’re away and ramping it back up before you get out of the car. But unlike most programmable thermostats, which rely on battery power, these smarties require a steady flow of electricity—that is, hard-wiring. So before you buy one, pop off the cover on your existing thermostat and look for terminals with letters. If there’s a wire connected to terminal C, you’re in luck. That “common” wire connects to a 24-volt transformer on your heating and cooling equipment and can supply a smart thermostat with all the power it needs. If there is no C-wire, call in an HVAC technician to do the job. Without a C-wire connection, some smart thermostats will tap the other wires to turn on the HVAC system and steal power from it, causing wear and tear, and reducing the equipment’s life span.