... :15years 2.Certificate:SRCC,CE,Solar Keymark,ISO 3.Deliver time:Within 3days water heat pump DescriptionVacuum tube58-1800mm co-axial ... 31mm5,Insulation:foaming polyurethane thickness:50mm or 55mm6,Optional electric heater:220v-240v 1500w/3000w7,frame material :202 stainless steel8 ... ,the tap water flow in the tank ,if the water is full,it will close the valve automatically solar water heat pump(CE,CCC ...