Heat Pump Thermostat Wiring Chart Diagram - HVAC - The following graphics are meant as a guide only. Always follow manufacturers instructions for both the thermostat and the HVAC system. Additional articles on this site concerning thermostats and wiring can help you solve your problem or correctly wire a new thermostat.

Heat Pump Thermostat Wiring Chart Diagram

Some HVAC manufacturers use other colors for additional control points and it is why we advise you to read the manufacturers instructions. These charts and diagrams only represent the basic system. It is possible your system is equipped with additional HVAC components such as a humidifier or electronic air cleaner. Depending on the manufacturer and the designer of the components will depend on how the additional components are wired or integrated into your system or thermostat.

Heat Pump Thermostat Wiring Chart Diagram

The Basic heat pump wiring for a heat pump thermostat is illustrated here. It corresponds to the chart below to explain the thermostat terminal functions. Before uninstalling the old thermostat take a picture of the wiring with your cell phone before removing the wires. This way you have a reference. At the minimum draw a picture of it referencing the wires, wire color and what terminal the wire is attached to what terminal. The photo and the drawing reference can be used later to make sure you wire the new thermostat properly.

Heat Pump Thermostat Wiring Chart Diagram

Heat Pump Thermostat Wiring Chart Diagram

Heat Pump Thermostat Wiring Chart & Diagram - Single Stage Heat Pump Wiring Diagram

Single-Stage Heat Pump Wiring Diagram

Heat Pump Thermostat Wiring Chart

That is for use for heat pumps. You should 100% make sure that you have a heat pump system and not an air conditioner with electric heating strips as it is a common mistake for people to misidentify their HVAC systems. Make sure you do not make these same mistakes others make. Air conditioners are different because the reversing valve and defrost controls are unnecessary.

Heat Pump Thermostat Wiring Chart Diagram

Additionally, remember the RC/RH jumper is only for a heat pump system that has one transformer. Does your system have two transformers? It is rare but still possible. If you have a conventional split system air conditioner or heat pump and there is a jumper from RC to RH, then you have a single transformer and do not have to worry about two transformers in your system.

heat pump thermostat wiring diagram

If you are having problems getting it to work it is crucial to make sure you have the same connections from the air handler to the thermostat to the condensing unit. Additionally, use our other resources here (other articles) for thermostat troubleshooting.

Heat Pump Thermostat Wiring Tips

  1. The above chart will help if you have a question of what color wire goes where? Wiring a thermostat has been designed to be easy. The colors such as Red is for hot and goes to the R terminal. Same with the other colors and terminals. However, depending on who wired the thermostat last, they may not have followed the wiring color code. Therefore, before removing any of the old wires, take a picture of the wires and where the are terminated on the sub-base of the old thermostat. Use your cell phone to take the photo for later reference.
  2. Always make sure you turn the power off before doing any wiring. Forgetting to do this may cause you to blow the transformer or trip a low-voltage breaker. Or blow a low-voltage fuse.
  3. You can find a comprehensive list for colors, what they, and where they go here –  heat pump thermostat wiring colors
  4. Your heat may be different than the one described here. The heat pump wiring diagram above covers approximately 90% of the heat pump thermostats.

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Heat Pump Thermostat Wiring Chart Diagram

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