How to Install a 4 Wire Thermostat
- 1). Turn off power to the HVAC unit by turning the switch off on the unit, if it has one, or turn the breaker off in the circuit breaker panel.
- 2). Open up the furnace access panel and set aside. Look for the control board where the low voltage wiring connects to.
- 3). Check to see what terminals the low voltage wiring is connected to. Typically, the red wire is connect to the "R" terminal, the white wire is connected to the "W" terminal, the green wire is connected to the "G" terminal, and the yellow wire is connected to the "Y" terminal for four wire systems. Put the furnace access panel back on.
- 4). Mount the thermostat wall plate to the wall using drywall anchors and screws. Check to see that it is level.
- 5). Look at the thermostat wires and strip the wires back about 1/4 inch if needed with your wire stripper.
- 6). Connect the red wire to the "R" terminal, the white wire to the "W" terminal, the green wire to the "G" terminal, and the yellow wire to the "Y" terminal on the thermostat.
- 7). Push the thermostat on to the wall plate until it clicks into place. Make sure the thermostat wire doesn't get pinched doing this.
- 8). Turn the power on to the HVAC unit and set the thermostat to your desired temperature. It should now accurately maintain that temperature for you.
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