The heat pump has a circulation pump that circulates water from the storage unit (geyser) through the heat pump. The heat pump has a fan that draws in the outside air and directs it over the evaporator coil. Liquid refrigerant within the evaporator coil absorbs the heat from the outside air and becomes a gas. The warm gas in the coil then passes through the compressor. The compressor increases the heat, creating a very hot gas that then passes through the condenser. The condenser transfers the heat from the hot gas to the cooler water circulating through the heat pump. The heated water then returns to the geyser. The hot gas, as it flows through the condenser coil, returns to liquid form and back to the evaporator, where the whole process begins again.