Marketing InformationIn HVAC systems, specifically in heat pump units, a ProTech® reversing valve is a key component that controls the direction of refrigerant flow between the evaporator and the condenser coils. The primary function of a reverse valve is to switch the heat pump between heating mode and cooling mode. The four-way reversing valves are used in heat pump systems, including central, unitary and room air conditioners, to switch between cooling and heating modes by altering the refrigerant flow path.