Why is there ice around my outdoor unit?

When a Heat Pump is defrosting it will heat up the outdoor unit by reversing its refrigerant flow to remove frost and ice buildup. Defrost cycles take place to allow for better conductivity with the air, and allow the system run efficiently. When this happens, water will be produced from the outdoor unit which will eventually turn to ice (this is the reason a stand or bracket, and
proper elevation are required on installation).