... :CCC,CE,ISO 3.Deliver time:Within 3days 4.Manufacturer solar collector tube DescriptionVacuum tube58-1800mm co-axial structure high borosilicate 3.3 ... ,and the cold water sink to bottom,then heat by solar collector.so the whole system is always circulatingcontinuously.3,The electromagnetism ... the water is full,it will close the valve automatically solar collector tube for solar water heater