... Keymark, 2.3 years warranty for heat pipe solar water heater 3,Simple installation 4,Anti-freezing -40 degree Newest heat pipe split pressurized solar water heater(CE ... that of the all-glass tube 2) The flow passage is inner closed and pressurized, no water or medium goes through glass ... to original quality problems 2012 top sale heat pipe split pressurized solar water heater(CE,SABS,Keymark,EN12976)