Why is there frost build up on the lines running from the ice box to the compressor?
It is normal that some frost builds up on the lines leading from the condenser to the cold plate – the amount of frost will depend on the humidity level as well as the ventilation in the space the line passes through, 12″ – 20″ (30 – 50cm) is normal. You can use pipe insulation around the line to reduce the possibility of mildew developing.