... solar water heater 1. 100L-1000L 2, CE/PED approved, high quality 3, OEM/ODM 4, Food material SUS304/316L Heat pipe ... indicator 6. Return circuit connector 7. Safety valve 8. Expansion vessel connector9. Return circuit connector 10. Wall mounting 11. Expansion ... vessel: 5L, 8L, 12L, 19L, 20L, 24L 12. Pressure resistance: 10 ...