If you replace your standard home thermostat you find the most common setup has either 4 or 5 wires running to your HVAC equipment. These include a 24 volt AC power wire, leads to switch the ...

Resideo, which makes Honeywell Home thermostats ... you might need to add another wire to serve as the common wire, which ...

Instead of using thermostat wiring, these thermostats work more like TV remotes. You aim them at your heating and cooling units and connect them to your home WiFi network for smartphone control.