Thermostat Wiring For Furnace And Ac

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.

Thermostat wiring for furnace and ac.

It terminates at your air handler or furnace. Furnace 24 volt transformer. The heating system will likely be a gas or electric furnace. Sometimes depending on the thermostat and the manufacturer the thermostat can be a dual heat pump thermostat.

The yellow wires terminate at your compressor contactor via an air handler. W terminal to the white wire. Notesome ac systems will have a blue wire with a pink stripe in place of the yellow or y wire. Label where the wires are connected on the thermostat.

Turn off your existing thermostat. Breakdown of colors and terminals thermostat wiring diagram for ac unit. The yellow wires connect to the y terminals on your thermostat. C terminal to the blue wire.

The yellow wires underneath your thermostat connect to your compressor. The white wire connects to terminal w in industry standard thermostats. The two 24 volt wires go to the r terminal and c terminal inside the thermostat. 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.

Red wire for air conditioner control power hot 1 the r terminal is the 24 volt hot feed from the control step down transformer. The transformer steps down 120 volts to the 24 volts the thermostat needs and sends out the 24 volts on two wires. Flip the furnace ac breaker to the off position. The white wire underneath your thermostat connects to your heating system.

G terminal to the green wire. Always refer to your thermostat or equipment installation guides to verify proper wiring. That will power the relay contactor or complete the circuit in the circuit board. They control your air conditioning system.

This diagram is to be used as reference for the low voltage control wiring of your heating and ac system. Or it can be used for an air conditioner and gas furnace system depending on how the thermostat is wired. Check to see if they match the industry standard listed above. Thermostats use 24 volts ac from a transformer to control a furnace.

Once your c wire is ready follow these steps to install your new thermostat. R terminal for the red wire. Y terminal to the yellow wire.