... , the electrical heater is 1.5KW, for 300 L to 500L water tanks, it is 2.5KW.* For copper coils, if equip with ... free, high strength, and resistance to corrosion by chlorine ion.2) New technology and new material. A special silicone is coated ... thickened material, so the service life is much longer. Split pressurized solar water heater(WSP)