Heat Pump Thermostat Wiring

What You'll Need
Wire cutters

You may become confused when you need to hook up heat pump thermostat wiring because of the number of wires. You must hook up at least 8 and sometimes 10 wires. The heat pump thermostat wiring must be correct in order for you to get the right amount of cooling and heating. These guidelines will help you complete your wiring project successfully.

Step 1 - Turn Off the Electricity

First turn off the mains electricity. This step will ensure that none of the wires you touch are carrying any voltage.

Step 2 - Identify Your Type of Thermostat

Before you proceed, you must know what kind of thermostat you have. If you are not sure, check the number of wires that stick out of the panel. Remove the thermostat, and you should find the wiring attached to the back. If you find less than five wires, you have a traditional heating device, but if there are five or more, you have a heat pump.

Step 3 - Work Out the Meaning of your Heat Pump Thermostat Wiring

Once you are looking at the thermostat's back, you will see wires of different colors. You should also find a series of letters down the sides of your heating system. All of these letters match with a different wire. For example, an "RC" wire will connect to the red wire, and it is the heating equipment. The "RC" terminal will also provide power to the other terminals, so you must ensure that it is plugged in correctly. If there is an RH and an RC terminal, there will usually be a short wire connecting them. The "G" terminal will attach to the green wire, and it controls the blower which helps cool the system. "Y" terminals are usually connected to the yellow and a compressor, and the white wire should be connected to the "W2" terminal. Make sure that you follow the instructions on your thermostat and hot water pump to correctly link wires and terminals.

Step 4 - Install the Heat Pump Thermostat Wiring

Look at the end of your wire. You may need to remove the insulation (the colored part of the wire) in order to see more of the wire itself. You can remove insulation with a wire cutter, or by peeling the insulation back with a pair of pliers.

Once you have enough wire, unscrew the terminal but take care not to completely remove the screw. Push the wire into the space created and then tighten the screw. Repeat for all of the terminals which need a wire. Replace the thermostat and restart the electricity.