C wires or varying colors apply to every thermostat, but blue C wires belong to thermostats attached to a heat pump. Blue wires are for heat pumps, like orange wires. This wire connects to terminal B on your thermostat.

Is the blue wire the C wire?

The Rh wire connects to the heating system. This wire may be red without an “H” attached, in some cases. Blue. The blue wire on the thermostat is the Common or “C” wire.

What does a blue wire mean?

travelers Blue wires are used as travelers, usually on three- or four-way switches (controlling a light from multiple locations) or as switch legs for things such as fans or lights. Yellow wires are almost always used as switch legs for outlets, fans, or lights. White or Gray.

What does blue wire mean on thermostat?

the Common wire Blue wires are also called “C” wires because they are the Common wire. C wires are necessary for any “smart” thermostat that needs to be connected to a power source 24/7, regardless of your heat pump type. Blue wires are for heat pumps, like orange wires. This wire connects to terminal B on your thermostat.

Is the blue wire hot?

Blue and yellow wires are sometimes used as hot wires. Blue wires are commonly used for travelers in three-way and four-way switch applications.