A method includes operating a compressor of a heat pump system and is selectively providing vapor to a vapor injection port of the compressor via a vapor injection line and vapor injection valve. The method further includes determining a frost condition of a first and second heat exchanger of the heat pump system and closing a vapor injection valve to prevent fluid flow into the compressor at the vapor injection port. A direction of refrigerant flow is reversed to direct vaporized refrigerant to the one of said first and second heat exchangers experiencing the frost condition. The vapor injection valve is opened after a first predetermined time period following reversal of the refrigerant flow. The method further includes closing the vapor injection valve and reversing a direction of refrigerant flow within the heat pump system once the vapor injection valve is closed for a second predetermined time period.