Dehumidifier icecing up

Three possibilities for coils icing up.

1. Low ambient temperature in the area where dehumidifier is located. If so, shut down and de-ice it. Then move the unit to a different - (warmer) - location and start it up.

2. Heating element - (which cycles periodically to liquify frost on the coils and allow water to drain) - is malfunctioning.

3. Low refrigerant level in the unit.