... pipe 15 years warranty 3.delivery:15 days 4.OEM split pressure solar water heater 1. that type have CE,ISO9001,CCC, ... keep water more clear,3. this product most for europe market, work wirth work station, that together complete autumatic, and can work ... connect with the solar energy, inside coil have special liquid for recirculate exchange hot, all that controlled by work station, if cloudy day ...