In a heat pump, what is the function of the reversing valve?

The function of the reversing valve in a heat pump is to change the direction of refrigerant flow. This is a critical component that allows the heat pump to switch between heating and cooling modes. When the heat pump operates in heating mode, the reversing valve directs the flow of refrigerant so that heat is extracted from the outside air or ground and pumped into the indoor space. Conversely, in cooling mode, the valve reverses the flow, directing the refrigerant to absorb heat from the indoors and release it outside. This bidirectional capability is essential for the heat pump to function effectively in different seasonal climates, providing both heating and cooling as needed.