Thermostat Wiring For Furnace And Ac

Y terminal to the yellow wire.

Thermostat wiring for furnace and ac.

The yellow wires terminate at your compressor contactor via an air handler. The white wire underneath your thermostat connects to your heating system. The yellow wires underneath your thermostat connect to your compressor. The yellow wires connect to the y terminals on your thermostat.

They control your air conditioning system. Turn off your existing thermostat. The heating system will likely be a gas or electric furnace. The transformer steps down 120 volts to the 24 volts the thermostat needs and sends out the 24 volts on two wires.

Additionally it will require a different thermostat and different wiring than an air conditioner. This function allows you to circulate the air in the house by using the fan in the furnace without heating or cooling the air moving through the system. That will power the relay contactor or complete the circuit in the circuit board. R terminal for the red wire.

In the most basic system this functionality is provided by use of a fan center relay and the low voltage wiring to the thermostat now will require a minimum of three wires for heat only. Always refer to your thermostat or equipment installation guides to verify proper wiring. Breakdown of colors and terminals thermostat wiring diagram for ac unit. Label where the wires are connected on the thermostat.

Or it can be used for an air conditioner and gas furnace system depending on how the thermostat is wired. A thermostat with five wires typically controls an air conditioner with a heating system. Notesome ac systems will have a blue wire with a pink stripe in place of the yellow or y wire. Sometimes depending on the thermostat and the manufacturer the thermostat can be a dual heat pump thermostat.

This diagram is to be used as reference for the low voltage control wiring of your heating and ac system. The thermostat is likely a digital thermostat that requires the c wire or the common wire to provide power for the thermostat. Red wire for air conditioner control power hot 1 the r terminal is the 24 volt hot feed from the control step down transformer. C terminal to the blue wire.

Flip the furnace ac breaker to the off position. Thermostats use 24 volts ac from a transformer to control a furnace. W terminal to the white wire. The two 24 volt wires go to the r terminal and c terminal inside the thermostat.

The white wire connects to terminal w in industry standard thermostats. Once your c wire is ready follow these steps to install your new thermostat. G terminal to the green wire.