R Wire Thermostat Wiring Diagram

The diagram below shows how a basic 4 wire thermostat is connected as indicated by the color code chart above.

R wire thermostat wiring diagram. 3 wire heat only thermostat r g w if you have a heat only system you may notice that your thermostat has three wires r g and w. It is a red wire and comes from the transformer usually located in the air handler for split systems but you may find the transformer in the condensing unit. Thermostat installation wiring diagrams. For programmable thermostats and smart thermostats c wires are essential for setting a schedule or having your heat or air conditioner turn on at a desired temperature while some units can run without a c wire even brands like nest recommend having one for optimal.

The basic heat a c system thermostat typically utilizes only 5 terminals. This answer has some diagrams that show how a simple single signal system works. Thermostat wiring and wire color chart thermostat wiring colors code. Color of wire and termination.

If your home s system of this vintage has provisions for air conditioning cooling then the thermostat wiring will have at least three wires some will require a separate r terminal for heating and cooling and will be labeled rh and rc now needing a minimum of 4 wires r w and a y terminal. Red now there can be two separate wires for this. Thermostat wiring diagrams for heat pumps heat pump thermostat wire diagrams. In these cases the signal wire from the heating system will be connected to r or rh while the signal wire from the cooling system will be connected to rc.

Heat pumps are different than air conditioners because a heat pump uses the process of refrigeration to heat and cool while an air conditioner uses the process of refrigeration to only cool the central air conditioner will usually be paired with a gas furnace an electric furnace or some other method of heating. If only a single signal wire is used the r terminal will be electrically connected jumpered to rh and or rc. If you re unsure of your system voltage you or a contractor should measure voltage using a multimeter. Yellow the yellow wire connects to your compressor.

G fan usually a green wire r 24 vac usually a red wire rc and rh are discussed later c 24 vac common y compressor usually a yellow wire w heat usually a white wire the thermostat is a set of contacts where g w and y are connected to r based on the following rules. Sensi thermostat is rated for 20 30 vac. Green the green wire connects to the fan. Orange this wire connects to your heat pump if you have one.

White the white wire is what connects to the auxiliary heat on your system. Sensi thermostat is not compatible with line voltage systems. R the r terminal is the power. Rc red wire power 24 vac rh or 4 red wire jumpered power 24 vac w white wire for heating enable y yellow wire for cooling enable.