Which component is energized through TH-1 when switching to heat mode?

In a heat pump system, TH-1 typically refers to a thermostat or a control circuit that is responsible for switching the system to heating mode. When the heat mode is activated, the RVR coil, which stands for reversing valve relay, is energized to enable the reversing valve to change the flow of refrigerant. This process is essential for the heat pump to extract heat from the outside air (or ground) and distribute it inside the building.

Energizing the RVR coil directs the system to switch operation from cooling to heating, allowing the heat pump to function efficiently in the heating mode. This is a critical function since without energizing the RVR coil, the heat pump would not be able to reverse the refrigerant flow and would be unable to heat the interior space.

Understanding this mechanism is vital in recognizing how heat pumps operate and the role of different components in the system, particularly in relation to switching between heating and cooling modes.