... ,Solar Keymark,ISO 3.Deliver time:Within 3days water heat pump DescriptionVacuum tube58-1800mm co-axial structure high borosilicate 3.3 ... ansorb the solar ultraviolet ray;then heat the cold water in the vacuum tube2,The hot water rise in the top of the water tank ,and the cold ... its valve,the tap water flow in the tank ,if the water is full,it will close the valve automatically solar water heat pump(CE ...