A heat pump system includes a compressor, a usage side heat exchanger, a heat source side heat exchanger, an expansion mechanism, a main refrigerant flow control valve switchable between cooling and heating modes, a gas reheat heat exchanger, a fan, and a secondary refrigerant flow control device switchable between first, second, and third modes. Refrigerant flows from the compressor discharge line to the main refrigerant flow control device in the first mode. Refrigerant flows from discharge line to gas reheat heat exchanger and then main refrigerant flow control valve in the second mode. Refrigerant flows both from discharge line to gas reheat heat exchanger and then main refrigerant flow control valve, and from discharge line to main refrigerant flow control valve without flowing through the gas reheat heat exchanger in the third mode. Refrigerant flows to the usage side and hot gas reheat heat exchanger in the heating mode.